Sorry to hear your having some problems, but overall, from what I read you might have to high of a water/humidity issue for cactus and succulents, add some perlite to your germination mix, dry out the growth area some, I use cinder sand here in AZ.. I might be wrong, but I'd also guess that trying to root succulents and cactus with some of the hormones might be a bit to "hot" for them, along with moister there probably rotting,
Allow the cut/wound to heal, don't use any rooting gel/hormone and just place them in a well drained soil mix.
Theres thousands of ways to do this, and each way is better for some people than others, so we could end up writing a book here.. We grow tens of thousands of cactus from seed each year and do allot of cuttings also, and I'd bet to say I don't use a pound of hormex 3 a year if any at all..
Don't give up.. your to close to stop now..

What genus specifically are you trying to get to strike?

Here is a link that might be useful: RSI Growers

I haven't picked one genus in particular.... I actually purchased a mixed flat of succulents and cacti from a grower somewhere outside FL. I have some African Violets that are from another grower, standard miniatures and trailing ones. I did order some crown of thorns and a few pads of prickly pear cactus. Also one succulent is a gasteria glomerata, as well as Mammilaria Sphaerica. Both of those can be divided when they cluster off. I also have "mother of thousands" kalenchoe plants which don't need anything to reproduce. I'll have to tinker with the humidity level in the greenhouse, all the plants are in draining containers, but the soil as you say might be holding too much moisture. I ordered some perlite and vermiculite to work on that issue with.

I have rooted both African violets and succulents with absolutely no hormone nor misting. In fact, misting these plants would make them rot I would think! As for African violet, I just cut a healthy leaf off the mother plant, stick it next to the mother plant and a 4-6 weeks later, you get little baby plants! I've gotten 4 plants to one leaf. As for succulents, I just cut a chuck off and root in soil outdoors. I've done this with jade plant and other succulents that I don't know the name of. They are the easiest; in fact, I've seen succulents break off from the mother plant and root themselves in the soil countless times.

How about adding perlite to the medium instead of vermiculite? Or just 100% perlite (which is what I will often do with house plants). I agree that the misting is not required for those plants. Hopefully, you've provided some protection from the heat and sun. I've not purchased any rooting hormone in years.

I think you may be using the wrong medium, and too much moisture.

Cut the succulent or cactus piece, and lay it aside, out of the sun, for the cut to dry. Otherwise, that cut will be more likely to rot.

I use grit, or sand mostly to root my cactus. Succulents can stand soils better, but no peat for either. When the cuts are dry, stick them into the chosen medium and set them aside. I would give them a good watering at this time, just to settle the medium around the cutting.

It takes a while to get roots, and patience is the #1 requirement for plant propagation.

For Violets, I found this old thread. This is the best way I have found to root them. I have rooted thousands of violets in this manner.

Good Luck!

Janie

Here is a link that might be useful: Easy Violet propagation

Awesome thread there thanks Janie! I've got some perlite on the way- gonna give it a try with that. I think my main problem is "over care" which of course kills them. I did some tissue culture propogation in college and had to do so much more care for those plants - I think I can't accept it could be as easy as popping the leaf in the rooting medium and letting it go! LOL I'll definitely give that a try. I'm also working on the succulent rooting - I've not let them dry out before I tried potting them or hormone coating them.. Thanks so much for the info!