Three solvents were chosen using previous testing data on their low flammability. Six (three per soil type) pre weighed aluminum coupons were assigned to each solvent for each substrate for a total of 18 aluminum coupons. Half the coupons were soiled with the glyconol wax soil (about 0.5 grams) by placing a small ball of wax onto the bottom third of the coupon, heating it with a heat gun to melt the wax, and then spreading the wax into a strip across the bottom third of the coupons. The other half were soiled with the Royco 27A grease (about 0.5 grams) by spreading on the bottom third of the coupons with a swab. After soiling, the dirty weights of the coupons were recorded. The coupons were then subjected to 20 mins of unheated ultrasonics in their respective cleaners. The coupons were left to air dry overnight before the clean weights were recorded.