This is very very old but I'd like to put in a bit of suggestion myself... I was pointed here by Shawn as I was asking him through PM about Hoyas.
If you can't find these types of tubes, I doubt if I can find them here in Manila, you an try out PVC Pipes of the same diameter, But maybe 1 meter or 2 meters and cut to lenght you need, then just a matter of finding a way to plug the other end, or just tie a net or something at the end to hold the cocochip in place. That wire mesh thing is a great idea too from Shawn!
Hmm wonder if this tube idea will work for Nepenthes as well
TTFN
Arvin