I tried this with honda prelude blue factory matts they were very nasty, I washed and scrubbed with brush, then tossed them in the washing machine. I then put them in the dryer. The ribbing around the edge became frayed. But I used a pair of scissors and snipped them off the matts came out great and looked much better. but I would not use the dryer from my experience unless it was the washing machine? No machines for me. I'll stick to hand, powerwashing or machine cleaning and air drying them, sometimes after steam cleaning my matts, I'll turn my heat on and direct it to the floor for 20-30 minutes, or hang them in the sun for awhile.