According to Arin Hanson from Game Grumps: Desert Jellies are what the
navy calls it when you jerk off in the shower, since you rarely get any alone
time except for when you're in the shower. If you jerk it too much however, it will clog the drain, and your "desert jellies" will
float back up to the surface.
This is from their BOTW playthrough btw.
"The shower
drain got clogged again," Person #1
said.
"What? How?" Person #2 asked,
"Desert Jellies," Person #1
simply replied.