Ive flown 60 degree AOB turns in Barons and Duchesses into the dead engine albeit lightly loaded and with 2 hours fuel. You just have to be very careful.
One would hope that your sixty degree angle of bank was a momentary overbank due to inadvertant loss of control. That can be forgiven. But to deliberately cause the aircraft to reach sixty degrees bank angle on one engine in a multi-engine aircraft to prove it can be done? Not a good idea...