The positive health effects of moderate drinking are apparently well
established. But, I was wondering if it was simply the result of being
a mouthwash.

I've heard that bacteria bred in the mouth are linked to heart
disease. Presumably, one way of taking care of those bacteria is to
use mouthwash regularly.

Since mouthwash contains alcohol, it occurs to me that people who
drink moderately are essentially consuming mouthwash with their meals.

Might there be any truth to this?

A professor of dentistry once told a friend of mine that beer is the
best mouthwash known to man.

However, it was at an academic reception, and a few people were
getting tired of the sherry.