A couple years ago I was alone in a customer's home, working on a tank. The skimmer (Turbofloter 1000) was unplugged when I got there. I was ready to leave, so I plugged in the skimmer. It put out wet foam, filling the cup in seconds. I worked on the stupid thing for about 30 minutes before I finally gave up and unplugged it. I called him later about the skimmer and he told me he'd put Stresscoat in the tank the day before.
I could have killed him.
BTW - I read somewhere Stresscoat could harm clownfish.