When my 120 grit SiC stone was worn down to nigh-uselessness, I scraped it off with a putty knife and used acetone to remove the adhesive. Then, I took an EZE-Lap 42C (bought from the maker w/o a base) and stuck it to the remaining metal piece with two pieces of double-sided "Scotch" tape. 3M's 77 spray adhesive works, too, but unless you're very stingy with it, it will make a big mess. The 42C is a 250 grit stone which cuts slower than Ben's 120 grit stone by quite a bit, but it's always the same height. It cuts faster than EdgePro's 220 grit stone and leaves a rougher finish that the 220 grit EdgePro stone removes.
The 120 grit stone from EdgePro requires a little work to flatten and it will wear down to nothing if you get a touch of edge-o-rexia, but it's really the best deal going for this system in terms of time and money spent.