It might work, but it sounds problematic.

You should be sure your water heater is set to the 120 - 140 degree range.

A tub of hot water as it comes form the tap sounds like a waste of money.
A plastic bag just big enough to hold the ball sounds good. Garbage bags are huge compared to the size of a ball.
Put it in a bucket just big enough to hold the ball.
If the ball is not soaked with enough oil to roll down the side of the ball, it could just soak back it as it rolls down the side. Maybe it's better to check on it every 30 minutes to just wipe it off.