Rochester Midland Corp Defoam it Anti Foam Agent 3.8L GALXBOY Clothing T Shirts View Our Range of T Shirts. Defoam it is ready to use and requires no dilution. Use wherever foam build up may be a problem. Specially designed for use with water extraction rug cleaning units to break down foam caused by residual shampoo left in the rug after normal cleaning methods. An excellent defoamer for use in wet vacuums or automatic scrubbers when used to pick up foaming detergents.