I use some Lowes $5 special rooting powder. The environment is more important than the hormone.
During rooting of a clone, that clone doesn't have a way to pull nutrients up through the soil so, it relies heavily on foliar feeding/lack of perspiration. You don't want the plant to perspire as normal, hence the humidity dome and foliar spray once or twice a day. Keeping your rooting medium (soil/rockwool) at roughly 80 degrees will help stimulate root growth with or without rooting hormone.
So here is a good environment to stimulate clone rooting, regardless if you use rooting gel/powder. Humidity of 80%-95% (use a dome), Heated medium (soil/rockwool) to roughly 75-80 degrees (heat mat), foliar feed at least once per day and pull dome off to circulate fresh air once a day.
You do not want your plants to transpire moisture through it's leaves like normal, meaning you really must have a humid environment during this time of a clones life (humidity dome)
My clones root in 1-2 weeks with a 95% success rate or so. (the other 5% are just bad clippings, too small etc)
ALso, your clones do not need much light contrary to what some suggest. I use one 2ft t5 floro tube and it stays around 4-5 inches off my clones while under the dome. Hope this helps
