When ds2 had a fungal infection in the nappy area it just got worse and worse even using the prescribed cream, until we switched to disposables for several weeks. Plus lots of nappy free time which was hard as it was middle of winter and we had a draughty house!
Even if you use fleece, wool, etc, the fact is that unless you take a cloth nappy off THE SECOND its got even a tiny wee in it, then it is a damp atmosphere which the fungus loves.
Disposables by the way they work, keep the skin completely dry. Its only by keeping the skin dry and eradicating the damp atmosphere that the fungus loves, that you will be able to get rid of it.
On the nappy rash question we always found camomile tea works a treat, we didn't socak liners in it but just used it on washable wipes or cotton wool.
Have you been to the docs about the fungal infection, it needs an antifungal cream and is free prescription for babies.