When I was dealing on a riverboat, I was priviledged enough to witness a small cleaning. Our casino used Paulson Tophat and Cane chips with a plasticised inlay, so they could take some moderate water abuse. I'll try my best to describe it, not that any home user would really have the opportunity to do this.
They took a piece of lexan with holes drilled on it, and laid a very thin wire mesh on top. Image chicken wire, but much, much thinner guage. They then tiled the chips to be cleaned flat out on top of this lexan/mesh board. It was a somewhat large apparattus, about 25-30 chips in height, about 50 wide. Another wire mesh was placed on top, and was secured by a clamped frame to the lexan board. They were immersed for a short time (20-30 seconds) into a tub of hot soapy water (they seriously had a big jug of Tide on the table) and then were lifted out of the tub. Using a hard plastic bristle brush, they then scrubbed the entire face of the chips in long sweeping motions. The wire mesh was then turned around to get at the opposite side, and the process was repeated.
After this brief scrubbing, they were submersed into another hot tub of water containing a clear sanitizing solution (smelled like beer to me...) They were then taken out, the lexan removed, and then placed under warm air dryers in the mesh until they were dry and could be stacked for storage.
They had a whole assembly line going, as one could well imagine, as our small casino probably had between 80-120k chips to rotate. The entire process probably took no more than five to seven minutes from dirty chip to clean chip.
Might throw some ideas at some others looking to clean your chips.
