If it's like
NPC Code:
_._
UOU
U=bucket, O=Bomy, _._=yoke/stick over its shell
Then if it's weighted just right, when it spins the buckets will go out with the centrifugal force, but the water will just get mashed down into the bottoms of the buckets without spilling. Moving quickly would be tricky, since Bomys have such slippery shells the whole yoke would probably go one way as they go the other, so yeah, it'd have to be strapped on like a backpack basically...