I am loathe to post cures here and don't worry it is not for asthma, but I find nebs often leave me with oral thrush especially if I have a bit of neb fest. I have taken to eating a pot of natural organic yoghurt for breakfast and the thursh has not re-appeared. I have tried several times not having it for for a while and it comes back, and then using it and it goes away again. Anyway just a thought for those plagued by oral thrush and who can eat milk based products.
ps it says on the pot probiotic I don't know if that makes a difference or not