50 years ago, in my elementary school, we put celery stalks in water with food coloring so we could see the color creep up the stalk. The leaves continue to transpire even without roots.
If my elementary school science class isn’t authoritative, here’s an article talking about water uptake in cuttings:
I’m with @elheffe702 and @Loneviking. Organic honey has worked better than aloe or any rooting gel I’ve tried.
I think the best results with honey are to dissolve a tablespoon into a cup or two of boiling water. But I don’t think that solution stores well.
I do know a guy that grows aloe vera and claims it works well too.
It doesn’t. But it can go right into your tea when you’re done with it if you don’t want to waste it! 
Thanks for all the info, much appreciated, will try a few different things and see what works best.