I have a self-proppeled HONDA gasoline powered lawn mower that is about 15 years old. I noticed that the rear grass catcher bag which appears to be made of nylon is getting hard to clean with a water hose, and the build-up from all those grass cuttings is having an affect in the vaccuming part of picking up the mowed clippings. The bag is still in good condition. The wife says no way in putting it in the automatic washing machine. Is there an inexpensive way or product to get it clean again short of buying another bag (may not be available due to the age of the bag). Will a proper mixture of Muratic Acid do any good, or will it damage the nylon. How about a good way to clean the build-up in the under-side of the mower, other than scrape, and scrape, and scrape?