They are quite common here and I never heard of anyone getting zapped.

Mine is 10.5kW and on its own wiring run with a dedicated 45A breaker. A pumped power shower would still likely have an electric pump on a 30A breaker if it's on the wiring ring used for regular sockets. Both types must be used with an RCD. I think in both cases we're a damaged seal away from potentially similar dangers.