I would be very careful getting any embossed poker chip wet enough to clean. They tend to fall apart. Any regular casino chip is OK to clean using plain soap and a toothbrush, just don't rub on any hot stamp area. Inlaid casino chips can be scrubbed but very old worn chips actually look a lot better when dirty. When clean they lose all detail. I hope I am not telling any trade secrets but a lot of dealers use rubbing or polishing compound to clean C&S chips. You can actually remove moderately bad cigarette burns from them this way. Other than that there is no reason to clean a C&S chip - they don't collect dirt. There are a lot of collectors who just don't clean chips. To me it is a matter of personal preferrence. I want a chip to look as good as possible. There may be more help on the club web site concerning cleaning. I know there are special products out there that work very well but I have never seen the need to buy them.