A few weeks ago I bought a pre-war Zeiss Sonnar 135mm Contax lens, which came in the maker's soft leather 'pouch'. The lens has some fungus, and is currently stored at low humidity until I have time to clean it. However when I have done it and want to try it out, I would be doubtful about using its pouch, because of the risk of re-contaminating the lens.

I have had this dilemma before with several cameras, and have sprayed the interior of their cases with a 50/50 vinegar/water solution, cleaning it off afterwards with clean water and a sponge. I thought I might as well risk some damage on the basis that otherwise the case is useless, though in fact it doesn't seem to have done any harm, in the short-term anyway.

However the Sonnar case is leather inside and out, and in very nice condition, so I don't think the vinegar treatment would be effective without soaking it in the stuff, which I am certain would be a very bad idea!

I have seen suggestions on this forum that moth-balls will kill fungus, though I was sceptical at the time. I've been doing some searches recently, and find mostly rather vague suggestions that moth-balls may prevent mould from developing (as opposed to killing existing mould). The most positive source I have found so far is this one, however the Wikipedia entry for naphthalene makes no mention of any anti-fungal properties. Does anyone have access to any really reliable information (as opposed to online non-scientific DIY-type sites) that confirms the effectiveness of naphthalene/moth-balls against fungus?

Another possibility is that exposure to ozone appears to be a proven means of killing mould, but I'm not sure if the 'air purifying' type of generator, which are easily obtainable, would produce a high enough concentration, or if the ozone would have any ill effect on the leather.

Does anyone have experience of successfully killing fungus with either of these methods?