(No need for apologies, ChrisE and Heathcliff. I've come to realise there are a fair number of words in Chambers that don't show up in my Oxford, and vice versa).
I did think that using fire for rid was a bit problematic, but then so is Chambers's definition for the latter, simply as a transitive verb meaning to expel. But that's not how we normally use it, is it? Heck, I'll have to trust the authority.