It's just tapping. You're using the happiness tap method, which doesn't involve resetting your clock at all, right? So it's just tapping based on what results you get after catching a level 50 and up pokemon. But go read my guide in case you want to try for IVs. You can do that after saving in front of the Daycare man and before taking the egg.
What I do is use an AR code to view your SID via a caught poke from your game. It has to be a useless pokemon you don't need to keep because I throw them away after. The code does not affect your game or the poke. I throw them out because going back in to trade it back is a waste of time.
So all you need to do is trade me one useless poke you caught in the game you want to find your SID.