A lot of people started calling for violence against Musk’s cronies at DoGE.

I don’t know if it was “a lot” or “basically all of them” though, /u/spez is a trumpet so who knows.

So technically, you are correct. The force is the water pressure provided by the piss being pulled down by gravity. Practically speaking, this force is negligible because all you’re doing is allowing the piss to fall, not forcing it downwards.

Basically, imagine you’re holding an incredibly heavy rock that does not have a gravitational field or air resistance. If you drop the rock, gravity will pull it down, but regardless you will not go up unless you apply force and throw it down.

Force = Mass * Acceleration.

Gravity is (approximately) 9.88 m/s^2.

According to a random Wikipedia page, ideal body weight was at one point considered 50kg.

This means that the following will find the point where you are perfectly neutral, neither rising off the ground nor being held down by gravity:

9.88 * 50 = M * A

Unfortunately, A in your scenario is 0, meaning that this is not possible no matter how much piss you have. This is because your urine basically just falls out of your body and isn’t being ejected with force.