Pour 1/2 cup baking soda followed by 1/2 cup white vinegar into the drain. Let it fizz for 15–30 minutes, then flush with hot (not boiling) water. Stubborn clogs, lint balls, or foreign objects
Insert a 50–75 foot drain snake/auger into the standpipe. Rotate the handle when you feel resistance to break up the clog, then pull the snake back and flush the pipe. Dissolving mild grease and detergent residue