Check this link. You learn something everyday around here.
http://bayloraids.org/cases/february2002/answer.shtml There is a list of ingredients for Miles mixture in the article.
Be sure to ask whether you are supposed to swallow it or swish & spit. You may wish to ask the doctor and pharmacist both. Some of these mixtures are not meant to be swallowed.
I am amazed that you didn't get any instructions with it - I would have somebodys head for that. Even my vet makes me wait for the instructions and correct labeling on the bottle.
I had ulcers that took a long time to heal and many problems with candidiasis (thrush). Plus everyone going through this treatment has a temporariliy damaged immune system so it makes sense to me.
Oh and yes, with the lidocaine, I would use it before eating but if you swallow it, it can mess up your gag reflex so be cautious - you don't want to aspirate anything into your lungs - it can cause pnuemonia.