We used ultrasonic cleaners in submarines to clean our ventilation filters and they worked pretty well. You have to use a detergent made for ultrasonic cleaners. I tried to substitute dishwasher detergent one time and we had a room full of suds and I almost suffocated. One word about gas though, there are safer products on the market that may take a little more effort. Consider the cost of your home if you're gonna keep gas in your garage. If you must use gasoline, then invest in one of the safety gas cans with flame arrestors. In my occupation, I get constant reports of fires where someone had their gas in one of those cheap plastic containers.
Fred Durrette
Summerville, SC