The phrase created by Anthony owner of the youtube channel Birdman and the phrase is typically used when you are just disgusted by a certain despicable act.
A play on the phrase "Scratch and Sniff" Smelling your own fart by cupping the air around your butt with your hand, after farting, and bringing it to your nose.
I hope my farts don't smell too bad ... I'm going tohave to "Catch and Sniff", to make sure, because I have a hot date tonight.