Hi Don and Joe-Diver,
I, too, read your posts as suggestions for prevention. However, since neither of you, or the others who replied, had a diagnosis, how could you offer meaningful recommendations?
If shark_tamer in fact was contracting external ear infections (otitis externa/swimmer's ear), then your ideas may proven helpful. But, if he was getting middle ear infections (otitis media), then alcohol and vinegar mixes placed in the external auditory canal would have no prophylactic effects.
After your posts were already up, shark-tamer reported that he seems to have gotten one of each type of infection.
See the point?
Regards,
DocVikingo