Bare vines are really tough to get to root and a young one will probably give you trouble as well. I think there is more potential for a young vine to photosynthesize and provide food than a woody one but it's still unlikely to root.
I guess you could try to water root it because at least that's easy to keep an eye on and discard if you see it's not working.

Mike

Thanks Mike. I posted on another hoya forum, and it was suggested to add 1/4 teasp sugar to quart of water. And water with it. I'm ready to try anything. If it doesn't work, I'll have to ask for another cutting. LOL

My simple old 'Silver Pink' is constantly putting out those long long bare vines, and when I knew nothing at all about hoyas, I just cut them off and threw them out. Now I let them grow a few feet, and IF I get an umble, then I obviously keep it, and THEN it puts out leaves after it blooms. I dont know why to this day why it does this. BUT I have rooted some of these 'bare stem cuttings' in plain water, but they had on them what I call 'root nubs' or the beginning of aerial roots? Once they hit water, they rooted and put out leaves. (I did cut the tip off, to make it stop growing longer, and hopefully put out roots.) That might help. I dont know.I am FAR from an expert, I need help with my current rooting issue, but hey, give water a shot! I think soil is not the way to go,for now. My 2 cents.