I got a total of 4 HK rooted using Rapid Rooters out of 25. None rooted in my mister. I dipped them in various gels/powders. Not sure which helped the most. It looks like HK prefers much warmer temps with 100% rh. I can set my mister from 60f up to room temp without using a heat source, but I can't increase the RH. Everything else is rooting fine using my mister. At least it's squeaky clean now, that should last for a bit.