That is never a good move. I had a machine de-energized and locked out and still managed to lose a finger. People don't realize how much power an electric motor has and forget that it produces all of it's torque right from the start. Couple that with the gear reduction on the gearbox, and there is some serious power even on a low hp motor.Worked in a mill that had several of these in the dust collection system that emptied into dumpsters. One got plugged and a guy decided it would be quicker to dig it out by hand without shutting things down! The paddles were metal instead of rubber. We never saw him again after the ambulance drove him away.