Here is an interesting link...
Tips For Growing Vandas and Their Relatives : orchid dynasty
It shows a technique that isn't quite semi-hydroponics but it seems to work for orchids that like plenty of air to their roots.
You could also plant it in red lava rock and a plastic Vanda basket. The rock keeps humid air around the roots and you won't need to water as often as a mounted orchid. I find red lava rock and a basket-type pot has worked very well for my Cattleyas that like watered well but need to dry quickly. I tried using LECA but I have returned to red lava rock for most of my orchids.