Very dehydrated oncidium, help?

[JordanLF]

I have a very dehydrated oncidium. It was that way when I repotted it about a week ago to try and help it. It was highly root bound and most of them were dead. I cleaned it up and had it in just water for 2 days while I was searching for a pot, and when I took it out of the water it had a few roots that were a lot greener. I repotted it in orchid bark but now I'm wondering if I should have just left it in the water. Wasn't sure if those do well in water culture though.
Any ideas to hydrate or on switching it to water?? Would be a big help