I had the same mat but 6' x 3 ' but the pellets were still stuck in the cats paws so they would track every place. Since i changed to the mat with holes about 1/2" thick 3' x 3', the pellets do not make it up past the first stair. Im in a town house so steps are right buy the CG. The pellets I use are the black sinking pellets from eBay. I purchased 10 Lbs 2 years ago just after i ran out of CG pellets(that might have lasted 4 months till i changed to Simple Green. I still have 6 lbs left. i don't recycle the pellets i just shop vac them up and trash them.
here is a eBay link that is the same pellets i use but the cost has doubled since i purchased them last.!http://www.ebay.com/itm/Porene-Black-Pl ... 19c8041f6c