You could always just animate a bucket on a chain to do whatever you want if the player is in the zone or pressing keys or shooting it or whatever.
Having it swing when bumped into sounds like someone may have been playing around with the ragdoll.
I have seen in footage where the head of a dead body moved when bumped into, so I can imagine using ragdoll as a work around for your effect.
If the bucket on a chain was rigged properly and the model was made a character, then it may be possible to set up such an effect for bumps.
I have never tried it of course, since I just installed v117 and I haven't had a chance to play around with raggdoll yet.
Just a thought.