Yes, jemanden bescheißen would literally translate “to shit onto somebody”, but it usually means jemanden betrügen i.e. “to cheat/betray somebody”, so Bescheißerle literally would translate to “shitters” but mean “cheaters”.

Cheating the rules imposed by the church somehow has tradition, e.g. a Pharisäer (Pharisees) is a coffe with rum and whipped cream, similarly to an Irish Coffee.