CLENID drain unblocker gel 1000ml You can easily open any type of blockage caused by oil, hair, soap residue and similar residues. You can easily use the gel in sanitary and drainage pipes made of plastic, PVC and other materials. Pour one-third of the gel into the area where the blockage is. After about 15 minutes, check if the drain is open by adding a little water to it. In case of severe blockage, pour half of the gel on the blocked area and make sure the gel works overnight.