TavernLayout

0 = Darkness
1 = Explored / Stairs Up
2 = Dead adventurer
3 = A Rat Faucet
4 = A Tiny Mansion
5 = Various Barrels

If you want to find visit the square with the Faucet, you simply need to do:

void squeeze_rat() {
   faucet = 1 + get_property( "tavernLayout" ).index_of( "3" );
   if ( faucet < 1 ) abort( "Mafia doesn't know where the Faucet is." ); 
   visit_url( "cellar.php?action=explore&whichspot=faucet" );
   visit_url( "choice.php?whichchoice=512&option=1" );
   run_combat();
}