Joy-soil

Becoming so excited and happy that you soil yourself on purpose.

"We came from behind with a 3 goal deficit to win the game. I was so excited, I joy-soiled myself. Cleared out 3 rows of people in the process"

tilling salted soil

It's a wasted effort. A fool's errand. Banging your head against the wall.

With that man she's just tilling salted soil.