Septic Cleanser from Bio S.I. Technology is an all-natural microbial and enzyme formula designed to break down matter in septic systems and RV septic tanks. One quart of formula is applied directly to the septic system each month to prevent sludge buildup and odor. It can also be applied to the lawn to aerate soil in the leachfield and reduce wet spots. 866/393-4786; www.biositechnology.com.