Step 4 · Clean the P-Trap and Inspect Washers

This is the step people usually slow down on. Go finger-tight first, then a quarter turn. No rush — replay the clip whenever it helps.

Take the removed P-trap piece to a utility sink, bathtub, or use a garden hose outside for cleaning. Use a stiff, flexible brush, like a bottle brush, to scrub the inside of the pipe. Use hot water and a small amount of dish soap to help break down grease and soap scum. Clean until the inside is completely clear of all visible obstructions. While cleaning, inspect the plastic or rubber washers from the slip nuts. If they are cracked, deformed, or brittle, you should get replacements from a hardware store.