The process of taking a shit, then solidifying it. The shit is then smashed up and frozen around your penis forming an eco friendly condom. When this "Gruddelpop" hits the warm air for the first time, it should make a popping noise, which is where the word originates.
1. Dude, I love the environment, this one chick, and I sure hate the materials of modern day condoms!
Well, why don't you make a Gruddelpop!
What a splendid idea!
2. Your sister loved how eco-friendly my Gruddelpop was.