you can also use those plastic scribbly washing pads made for dishes. they're like long shreds of plastic or nylon all bunched up and then stapled together somewhere and made into a ballish thing. they clean out the grooves, but eventually the mat gets so many grooves that you end up unable to cut without skipping, or worse, falling into a groove and following that wrong cutting line. at that point i flip it over and it's like a new one without lines. it really extends the life an entire life-span. which is very nice given the cost. :hunf: