I think he may be getting meths mixed up with the bottle of blue no-rinse pet shampoo, which for some unexplained reason is on the top shelf of that unit. I found that bottle a couple of times when we were looking :-D

I left the two burners out, assuming the contents would evaporate quickly away, as they have in the past, but one of them was very full of liquid and I had to turn it out and give it a good squidge to empty. Dunno if that's relevant to flamability.

We could perhaps try raising the bowls a little higher above the flame next time. Not that I'm objecting to burned cheese, rather the opposite...