Hi Danny,
I've been using Medina Ag's "Liquid Humate" for years. In propagating cuttings, I do not use it as a rooting gel, per se. I did dilute it into the liquid I used to soak my sphagnum moss in. So the roots would grow into a fortified sphagnum moss. I also use it as part of the drench when I transplant a tree (either into the ground or another container). A few years ago, there was some discussions in this forum regarding the "fatness" of roots and whether it could be contributed to humic/fulvic acids. It appears as though it works well for what I use it for (and I certainly wouldn't consider it a panacea). Looking back at pics I took in 2005-2007, it appears as though my roots are fatter now, but I do not consider myself a scientist and have not really identified/eliminated other variables which may have caused the effects. I'm not necessarily endorsing the product. Rather I am saying I use it even if the results on cuttings are marginal, it is cheap enough (about $20/gal and diluted 1oz:1gal) for me to continue using.
~james