I really don't think that burning a line an inch long and 1/16th of an inch thick at the bottom of a stem is going to release any significant amount of toxic cl

I really don't think that burning a line an inch long and 1/16th of an inch thick at the bottom of a stem is going to release any significant amount of toxic cloud. A tiny bit if you're right there next to it, sure, but it would be dissipated within a few minutes.