My Vanda's down to 3 leaves

[Fredmax]

It's not looking good for my Vanda 'Robert's Delight'

It was a picture of health 3 months ago, but another victim of my new hothouse. I hadn't understood why it was losing leaves so assumed lack of water. It had a distinct yellowing from the apex of the leaf that would then spread outwards and then the next leaf would do the same. I've resigned to accept this one is not going to make it, but thought I'd ask if there's hope for something I can apply (or chop the base and hope it grows roots?).

I understand it has got a fungus like many other of my plants, and have dipped it in phosacid, sprayed a chlorine based treatment and doused it in cinnamon powder, all trial and error remedies but the fungus is still winning and will be down to 1 leaf soon