How to Unclog a Main Sewer Drain. If your home has more than one clogged toilet, bath, shower or sink you may have a clogged main sewer drain.This condition can cause a foul smelling mess if plumbing fixtures upstream of the clog continue to be used and sewage begins to flow out of lower lying drain openings inside your home..Clears sewer and lateral lines. Our Main Line Cleaner is a non acid formulation intended to clear main sewer lines and interior lateral vertical lines of all obstructions. .Frequently Asked Questions and Answers Clog Hog Sewer Jetter Drain Cleaners.At All Clear Sewer Plumbing, we help you get the clog cleared. With over years of experience, we unclog and repair floor drains, bath tubs,s, laundry tubs, toilets, and grease traps..