How best to clean unfinished wood pieces.

I've just bought some cheap wooden vintage 2.5" pieces off ebay to use with my 12" travel set board.  They are probably from the 1950s-1960s (TSL is the brand) and are in great condition.  However, I'm wondering how best to clean them to brighten them up a bit.  They are unfinished raw boxwood (ebonized for the black), so I'm not sure what is best, and safest, to use to clean them. Or is it best to just leave them as they are?

Wood loves wax! But beware, no silicon, no water in the ingredients. If you can try bee wax.

Thanks for the responses! I like the idea of the shoe polish. However, will that, along with the brushing and buffing, actually remove the grime that has built up over decades of handling, and is more noticeable on the light pieces? Or will it just seal it in? I'd quite like to clean up and lighten the wood a bit if possible, to take away its current slightly dull, dirty appearance.

I'm guessing that the use of any kind of detergent to remove any of that grime and dirt is a bad idea, correct? Even on unfinished pieces?
I think I might try the polish. A bit of shine will bring the pieces to life. I already have black polish, and the neutral is just as cheap to buy. Thanks for the tip.

I am convert to shoe polish on some sets and I love bees wax too.
Not combined … rather on some sets I use shoe polish and on other sets I use bees wax.
Check this out: https://m.youtube.com/watch?v=v57dRyYAlXk
Regarding the grime on older pieces … I know this isn’t going to make sense but I’ll try anyway…
…. there’s dirt and dust and then there’s the patina of age - I find careful rubbing with a damp cloth or 0000 steel wool is sometimes useful to removes the dust/dirt/grime but does not change or take away the signs of age … or even, apply the bees wax with the steel wool.
Also note - and again beware - using a bees wax oil like I do is wonderful but depending on the wood - it can deepen the colour. One way to see the possible effect is to use a damp cloth on a piece and you’ll see the effect … if you don’t like what a smear of water does … don’t be applying a beeswax oil. Personally, I love it …. I can almost see the wood sigh with relief as it is nourished and the grain pops.
One other point, let’s say a dark side piece is scratched or has an ugly scar that isn’t patina that has resulted from play - rather it’s just an ugly scar - shoe polish can help cover ugly stuff like that too.
Caveat - I am not a woodworker nor a professional chess piece restorer - so please take my thoughts with care (and a grain of salt) … it’s just my experience and if I had some truly, valuable antique pieces - I would take great care and potentially use a professional or fear doing something that I thought was restorative but actual changes the pieces and/or reduces the value.

Shoe polish is not a cleaner. It's a wax based stain.

For cleaning for the purpose of removing dirt, grime etc., and prior to using any other treatment such as stains or shoe polish, you can use a light solution of water & dish detergent with a soft cloth, then quickly rinse and towel off any residual/excess water/moisture, and allow the pieces to thorougly/completely dry prior to applying andy other products, stains, polishes, etc.

This is great advice and info, guys. Thank you for your input. Much appreciated.

@Powderdigit is a modest, cheerful, and careful fellow. Though I have never met him, it is easy to glean from his helpful posts. His (pictorial; within this Forum section) efforts to refurbish and enliven old, outcast sets and pieces has been personally inspiring. Like he mentions, and I can affirm, the old wood seems to spring back to life with a tender application of wax and/or oil. Glad his experience has found its way to your thread @antonius67 !

Very kind words @PWalker1 - thank you…. And that set you’ve pictured, is that something you’ve reconditioned yourself? It looks like a gem. 👍

I learn a great many things as each day and year passes. The above pictured set, @Powderdigit, is my first purchased set about 30 years ago. From a Mall Store called “It’s Your Move,” in Boulder, CO, USA. (Idk if the store still exists?)

The King’s height is 3 inches. That set has seen a lot of action: from the dormitory hallway floor, summertime cookouts, to battles versus close friends and acquaintances.

I am sorry to say, that although it has been loyal to me in all that time, I had been neglectful—out of ignorance. It has an awful gasoline stain (bottom R corner) from travel in my vehicle’s trunk, it has been repaired and reglued in a high school woodshop, and recently [after reading up on many others’ CB&E posts] it underwent a light sanding and spray (re)varnish.

So, to sum up, yes my Ol’ Lady has recently been given some better care. And, like you and others recommended—the pieces really drink up the wax/oil mixture.

Thanks for showing love, from afar.

I have an old tin with carnauba wax. Best there is.

Update - I took on board all the valuable advice given and proceeded to work on this humble little 2.5" king set. I first gave the pieces a light clean with a toothbrush and very dilute dishwash liquid, rinsing afterwards. A few days later, I applied black and neutral shoe polish and buffed with kitchen paper towel. I'm quite pleased with the result. A very cheap, dull-looking set has come to life somewhat. It was useful to try this out on a cheap set, before attempting the same on a more valuable set.
Before:

After:

To clean unfinished wood pieces like your vintage boxwood items, especially considering they're ebonized, it's recommended to avoid harsh chemicals and opt for gentle methods. A beeswax furniture polish can effectively clean and brighten the wood without causing any damage, providing a safe and natural solution to maintain their condition and enhance their appearance. For more info visit https://www.theindustreebar.com.au/waxes-polishes.

wow that came out good, what shoe polish did you use?

I have a boxwood and ebonized boxwood set with rooks whose tops aren’t polished, and was planning on trying Lord Sheraton Caretaker Wood Balsam, a blend of pure beeswax, pine turpentine and linseed oil. It contains no water or synthetic waxes. https://www.rustins.ltd/lord-sheraton/our-products/wood-care/caretaker-wood-balsam

I used black and neutral Kiwi Parade Gloss Prestige shoe polish. It's easy to apply to the tops of rooks, or other recesses, if you apply with a brush. I also applied the shoe polish to an old Regency set, as pictured in this thread: https://www.chess.com/forum/view/chess-equipment/the-french-regency-set-a-mystery-revealed?page=3#comment-98706239

OPs question was "what is best, and safest, to use to clean...unfinished raw boxwood (ebonized for the black)?". While I agree that shoe polish is good for treating chess pieces I´m not sure that it´s ideal for cleaning them.

For dirty unfinished boxwood I´n use very fine sandpaper ot steel wool. For ebonized pieces i damp cloth, preferrably some micro fiber one. In Sweden we have soap infused steel wool (Svinto) that would be my next step if the above were insufficient.

While shoe polish is OK I wouldnt apply it on dirty pieces.

Shoe polish will work well. Just use caution and have good ventilation if you're going to engage in a prolonged session of polishing. Shoe polish (Kiwi) contains a measure of Stoddard solvent, (White Spirits) originally formulated for the dry cleaning industry and is a known toxin to affect negative reactions in some individuals. This is what gives it the petroleum odor. I'd prefer using polish of higher concentrations of pure beeswax and carnauba wax myself. With proper caution and knowledge, i doubt that shoe polish will affect you in small doses, just know what you're using. BTW, if you like the Kiwi product, you may want to stock up as it appears to be getting a bit more scarce.

Point well taken! I'd suggest Howard Clean A Finish for cleaning  wood. I've used it on old wood products and work quite well. Thank you for steering this back to the OP.

May explain a few things

Would linseed oil work to clean it?