While generally a promising approach, in the case of St Pauli, Hamburg it might be different. Yes there are lots of homeless people, but there are also LOTS of randoms going there to get drunk and be on their worst behavior. Its part of the spirit of that place.
Anyways “not by authority” is bs imo. An electrical fence is also “direct feedback”, or razor barbed wire and you wouldn’t dare calling those non-authority
Never let them know your next move, see above