We had one of these. Just the dribble of Plastigoop on the outside of the bottle was sticky and made a mess of the styrene. The hotplate was indeed stovetop hot. The toy came with a handle made of spring steel (like a striker for a butane torch) with ends that fitted a slot on the molds, and you’d squeeze it to insert or release it. It took a few minutes to heat up the plate, then another several minutes to set the plastic. We both got small burns on our fingertips, but never got seriously burned by it. (Probably because the small burns taught us to be careful with it.)
We made lots of bugs because they were small and didn’t use up the precious goop, but I think my favorite was the huge long tailed toad. The cavity held about half a bottle, so I only got to make a couple.
Toxic or burn hazard? Didn’t matter, it was just a lot of fun! I remember playing with those bugs for many years after we ran out of goop.
