a rooting hormone will only reduce the time required for a plant to root. This reduce time in many cases insure roots will form befor the the cutting dehydrates & dies....
If use hormone to strong will/may burn cutting & a strengt to weak then now reduce time achieved...

Rooting hormone keeps the stem protected from fungus which will cause stem rot.
I use a liquid rooting hormone so I can change to a stronger solution when the cuttings become more woody.
soft wood cuttings get 1 part rooting hormone to 20 parts water and dip 5 to 7 seconds before sticking.
then hardwood in the late part of the year will be like 5 parts or so for 20 seconds before sticking them.
I use course sand like you mix concrete with so it will drain good.
Play sand is fine and will retain moisture causing fungus and rot to form.
I mist 12 seconds every 10 minutes from 8 am to 8 pm