Liquid drain cleaner is a very harsh chemical compound that can damage metal pipes. Overuse of this cleaner can eat holes in your drain lines and cause them to leak. Over time, these small holes can become large, and they will need to be replaced. So, if you hire an experienced and certified plumber, they never use chemical cleaners to get rid of clogs. Instead, they use tools like drain augers and hydro jets to physically remove blockages. This insures that the clog is completely removed. Also, these tools can clean out the entire drain line, which will make your sewer system work properly for many years to come.