Really interesting reading this thread. I was going to try and grow/make penicillan but I think I will give that a miss after what I've read.
Lots of people seem to be asking about natural alternatives. I've come across one that has had a some medical testing and that seems to be excellent at killing bacteria. It is called Manuka honey and is only available from New Zealand.
Bees graze on manuka or tea tree plants and then produce their honey. Honey has good antiseptic properties anyway but manuka honey has an added factor that kills bacteria.
Scepti I'd like to hear if you've heard of manuka honey and if so what do you think? Reading your posts I'd say you know a great deal more of these things than I do!