Hi Paul
Be warned... Hot vinegar smells like.... Err... Can't think of the word to describe it but it's definately bl**dy horrible!
Vinegar is just acetic acid, maybe pharmaceutical grade would be slightly better as it doesn't have impurities in it. Thinking about this, is it really necessary to use acetic acid or will any mild acid work?, why not citric acid?, as that doesn't have the pungent smell... Just thinking out loud here...
In any case definately do this outside on a breezy day as i'm sure any type of vapourised acid in an enclosed space can't be good for you
Jem