Remove Seized Corrugated Supply Line Connection

What happens here

When confronted with a stubborn or seized connection on a corrugated toilet supply line at the shut-off valve, the video demonstrates a technique to create working space. First, ensure the water supply to the toilet is completely shut off. Place a small container or absorbent towels beneath the connection to catch any dripping water. Use channel-lock pliers (such as Knipex Cobras or similar robust adjustable pliers) to firmly grip the plastic compression nut or handle of the corrugated pipe where it connects to the shut-off valve. Simultaneously, use a standard adjustable wrench to hold the shut-off valve itself steady; this prevents the valve from twisting and potentially damaging the plumbing behind the wall. Apply controlled force with the channel-lock pliers, bending the plastic connection back and forth until it breaks. This action exposes the underlying metal connection, allowing the adjustable wrench to then directly engage and loosen the metal nut from the shut-off valve. The presenter successfully removes the metal nut after breaking the plastic.

Goal: Effectively remove a seized corrugated toilet supply line connection.