I was skeptical when I saw this, but as my hamster Jasper was using his bed as a toilet as well as a place to sleep, I had to do something! I bought this, followed the instructions, and although I've not 'seen' him do his business in it, he definately is! After the first week there was 'clumps' in the potty!
The litter clumps, making it easy to clean the wee out of. The box says every 10 days, but I clean it every week, as Jasper tends to kick the litter about a bit.
The litter isn't expensive either, I think it cost me around £7 for three boxes on ebay, and I've still not finished the first box since the middle of May, but I'll be buying it from Amazon from now on as its cheaper!