I should have mentioned that whenever you a cleaning a type of chip for the first time, try it out on a low cost chip first. Try to use a similar chip that is still in use in a casino. Worse comes worse, you can always cash it in.

Never, never try to clean a chip with a plain paper inlay. Most inlays have a plastic coating to protect them. Some early chips have an unprotected paper inlay. Water or any abrasion will damage the inlay.