Here’s a clear, helpful text on the subject:
Wrap a plastic bag around the brush head, secure it, then use it like a plunger—push and pull vigorously to create pressure.
Stay calm. Most clogs clear with patience.
Squeeze a generous amount of dish soap (about 1/4 cup) into the bowl, then carefully pour a bucket of hot (not boiling) water from waist height. The soap lubricates, and the water’s weight helps push the blockage through.
Straighten a metal hanger, leaving a small hook at one end. Wrap the tip with tape to avoid scratching porcelain. Gently work it down the drain to break up or pull out the clog.
