In reply to TobyA:
No, the smell disappears pretty quickly. It is very effective and cheap in my experience. Vinegar has been an essential self help ingredient probably since civilisation began until the modern chemical industry made available more expensive and not always so effective treatments.
If you add some hot water to the vinegar the footbath becomes quite pleasant. Add sea salt and you have an aroma of salt and vinegar crisps
I still dissolve boric (used to be called "boracic") acid crystals to make eye drops - had this from my mother who used it to treat conjunctivitis when we were kids. So bad that our eyes were so stuck together with matter in the morning we had to walk blind to the bathroom. Her treatment cleared it up pretty well without any doctor visits
Come to think of it it would be quite easy to carry some for camping (cleansing of cuts etc), but going abroad with a little bag of white powder crystals could prove troublesome
Post edited at 10:59