If Drano and other commercial chemical products to unclog drains are off limits to homeowners with septic systems, what alternatives can they use? Often just using a standard plunger is sufficient to clear the clog. Note that bathtubs often have an overflow hole that needs to be covered by a washcloth (or something similar) before plunging. If plunging doesn't work on its own after a dozen or so vigorous pushes of the plunger, Mains recommends trying a mixture of baking soda and vinegar as a natural method of breaking up the clog. Use one cup of baking soda and one cup of vinegar mixed with two quarts of boiling water. Be sure to flush the mixture out with more water after about fifteen minutes of use. There are also commercial unclogging agents that claim to be natural products, but these are harsher than the baking soda and vinegar mixture and don't work any better, so Mains recommends sticking with the mixture above.