I keep a airtight box of cigars and the best tool to keep the humidity ideal is a Boveda pack. They come in different humidity levels, but the idea is if you get Boveda 75, it will add or subtract humidity to get to there. Has anyone tried using the packs in a box for rooting?
I have been keeping my makeshift humidor at 69% humidity for 2 years now with the same 2 packs. They work forever essentially and are very easy to use. Also, never had an issue with mold since they can reabsorb excess humidity. If someone would be willing to donate 10 relatively identical cuttings of any common variety I would post progress on here. I would try 5 cuttings at 69 and 5 at 75. Place in a baggie and forget, no brushing, no airing out, just waiting. As cigars are very prone to mold and it works with them, I think this could be a mold-proof way to root.
DISCLAIMER: JUST A THEORY! IF YOUR EXPENSIVE CUTTINGS DIE THIS WAY DON'T BLAME ME! :)