I think the stuff out there now is the tamer stuff, for keeping buffet tables warm. I tried some about five years ago and couldn’t get anywhere near a boil.
Now, 100% denatured alcohol will get the heat going and you don’t have to waste any unburned fuel.
I think the stuff in SEA prolly had a little nape and mogas in it ;)
We used it for emergency heat if stalled out in Alaska in winter.