Are you saying that you want to root a cutting that has no leaves? I wouldn't do that. I'd try to get it to put out some leaves first. Maybe it needs a re-pot?
ONLY as a last ditch effort(if you are going to toss it anyway) would I try and root a leafless cutting.

Hoyas are generally rooted in good draining soil & perilite mixture. I've never heard of sand.

FB,

Leafless cuttings don't typically root, but that doesn't stop me from trying sometimes. I'd do it in pure perlite, though, or hydroton. Either way, keep some water in your saucer to keep it moist until it roots. It could work, but if it doesn't, you've done nothing more than waste a bit of rooting space. And cutting off that long leafless vine will encourage new growth, so it'll be good for the mother plant.

Denise in Omaha