First time using hot mud. Questions and feedback.

First time using hot mud today. After being told I shouldn't use pre-mixed mud with mesh tape. Do you typically just mix it in an empty bucket and then throw it away after? How much do you allow to go down the drain? I would not dump leftover mud down the drain but I did use it routinely for rinsing off hands and tools. Hopefully diluted it enough and let the water run long enough that it won't be a problem?

I mixed too much water in the first time and it was like a liquid with a few random clumps of mud. I redid it and added just enough water to dissolve the dust, and maybe a tad more. It was difficult to reach into these corners with wire and garage door rails in the way. Behind the drywall patches is conduit coming in at a weird angle.

It was thick enough that it was difficult to move my fingers when they were completely covered. It was hard to get smooth when applying and kept leaving knife marks. Would this be why? I've had the same problem in the past trying to use Spackle as mud, before I knew better.