It can be done, and can work
I would not go near it though as Its rather chilly here so keeping vanda roots moist for longer periods without real drainage would probably be a real rot
I have found using hydroton balls as media, but not sitting it in water to be good with paphs though, so as long as abit more time was given for vanda roots to dry i guess i could pull it off, but i like mine in vases
It is down to personal conditions really, it could work