As the original liquid seal barrier dissipates over time, simply replenish by pouring Odor Lock directly into the cartridge, then let Odor Lock do the rest. Odor Lock floats on top of urine, water, and other liquids to create an effective seal that locks out the offensive odors that come back up through the drain. Extends the life of your waterless urinal cartridges and deodorizes the area with a fresh cucumber melon scent.