I've heard others say they find it easy rooting Hoya's in water but for me it's never worked. The cuttings always end up rotting, or they grow those thin watery roots and once potted up never seem to acclimate and grow a good strong root system. So, nowadays I pot up my cuttings just like any other plant. I use a very well draining potting medium that consists of potting soil and a lot of orchid bark mix. It makes for a chunky, fast draining mix but that's what works best for my growing conditions and I don't have to worry about rot from over watering or too much rain etc.
I used to have two very large Hoya Compacta (Hindu Rope) plant but lost them to a winter freeze a couple of years ago. It's not a particularly favorite Hoya because with all those twists and crevices, the HIndu Rope was a mealybug magnet during the summer months. I remember having to sit for an hour or more with q-tips and isopropyl alcohol trying to remove those little creepy crawlies!
Here's the database link to the Hindu Rope Hoya:
Hindu Rope Hoya (Hoya carnosa 'Compacta')
