I know this was just a demo, but that pipe didn't look like it had much rust on it to start with, light surface rust that could have been removed with steel wool/sandpaper
Use shop towels to keep substrate wetter. I wrap shop towels around pipe and tape snug dry, saturate and then plastic wrap. Or, wet first and mold to weird shapes, then cover. More goody available to do even more work. Closer to the full submerge results. And the used towels do much of the cleanup coming off.
Hey how’s it going man ! I just ordered mine and it gets here today. It’s to put on the top of my rusty roof. I plan on sanding it down first then covering it with siran wrap. Can I wash it down with a water hose or no ?