Do not flush for 6-8 hours. The quart of mixture poured into the bowl pushes one quart of water and mixture out of the bowl into the stack. The enzymes and bacteria carried out in the quart leaving the bowl are deposited on the sludge coating the pipe. In the following 6-8 hours they embed themselves in the sludge so that when the toilet is next flushed they will not be flushed out.