Woul I t be a stupid idea to go inside say a 55 gallon drum filled with water with a straight jacket on?

Or is cuffed feet and hands enough?

Im just not sure if the audience would see anything thrilling or cool about escaping with the lid still on. . behind a curtain.

You're overthinking the escape. The fact the the locks are on the outside of the drum already makes it impossible. Adding the jacket does nothing for the effect except add to your level of difficulty. Now, if the container were clear--and the audience could see you struggling--you might have something special.