I have posted my philosophy before and there are differences in opinion. I personally prefer, in most cases, the game worn appearance of the chips. The exlusion to this are LEs or other chips that weren't meant to be played. If I find one in play that is in good condition I will, carefully, try to do a more thorough cleaning. Along with the critics, I would admit that I do not like my chips to feel dirty when I am handling them though. They can sometimes be kind of gross. For that reason I lightly clean them to take the loose and recent dirt and crud off of them. However I do not engage in any scrubbing or deep cleaning. Sometimes, I have noticed, the dirt gets into engravings or stampings and actually enhances the designs and makes some of these features easier to see and appreciate. I usually take hand soap and apply it to my hands. Then I put the chip flat in my hand and rub lightly around a little and then rinse and dry. I never use any abrasive or brush etc. because I never know whether the design or stamping will come off. I have seen some chips like the NY NY $1 chips where the seller in an auction sent them to me taped in stacks with scotch tape. Even after delicately and carefully removing the tape the design started to lift in some places. I have noticed some chips where the design is simply a decal or sticker and of course with gold hot stamping... Due to these reasons I never know if using a toothbrush or other abrasive or scrubbing device might remove the designs. Also harsh chemicals could cause damage also. Therefore, it is my choice to not take a chance. Simple mild soap and water and a light rubbing with flat fingers or hands. I would rather have them show their age with some of the discoloration and hardened dirt than ruin the chip.