Yeast works in septic tanks by breaking down carbohydrates and starches. The tanks are rather expensive to repair, and you need to take proper precautions to keep your septic tank functioning properly. Commercial treatments can be expensive, and some even contaminate groundwater. Essentially, you do not want to kill the bacteria that live in the septic tank by flushing things like bleach and antibacterial soaps because the bacteria helps to break down the waste that helps keep the septic tank functioning. Yeast helps to stimulate the bacteria, and it helps prevent foul odours.
Pour 4 cups of water into a medium-size saucepan. Place the saucepan over medium-high heat.
Bring the water to a boil. Add 2 cups of sugar and stir until it dissolves.
Remove the saucepan from the hob. Add 2 cups of cornmeal into the solution.
Allow the solution to cool down to room temperature. Add two packages of dry yeast.
Stir until the yeast dissolves. Allow the yeast to froth, which will take around 20 minutes.
Pour the yeast mixture into the toilet bowl. Flush the toilet twice, waiting until it completes the first flush before you flush it again.
Pour this mixture into the toilet at night, to give the yeast at least eight hours to work without flushing.
Septic tanks still need to be pumped regularly. This is not a substitution for regular septic tank pumpings.