Paint “sludge” is just pigment. Take it out and put it in another container and save it wet. Take some out and add linseed oil and you have a nice “neutral” paint.
I would never dump my paint thinner in our streams, it could react with all the Benzene already leached into the beds from the large pharma factories nearby............. Sad but unfortunately all too true. I may be a bit jaded but the leavings from our artsy endeavors is in no danger of causing a cespool in an already well polluted and frequented one. That being said, HHW's are more common then you think and most of them are extremely helpful and very welcoming if you want to bring it to them.
Very cool! Yeah it’s a pretty good way of managing it. I was using the ziploc but they kept tearing and the bucket was getting dirty… as for the screen, no. I just use simple green but it doesn’t work that well. While typing I had an idea of soaking in a Dawn dish soap and water. I bet that would break it down pretty good. Gonna have to try that. I saw one artist state he just removes his screen each time, wipes it and that keeps it clean. I always forget… do you have something you use?