I use Sani Chips or Reptizorb liners.

I change the liners when they are soiled.

I spot clean the Sani-chips and change them out completely every few weeks or when there is a blow out (or somethimes if they spill all the water).

I do not mind it when they go in the water dish. I mostly use disposable deli cups, so just toss it and grab a new one.