Good morning and Happy Holidays,
Lots of good info here. I'm an old time grower and have seen trends come and go over the years. Like Missnu suggested, Rootone powder works good and is an old standby. With all cloning powders and gels, never stick a stem into the main bottle. You then contaminate it for future use. More critical with gels which can become infected. Pour some out to your work space and then discard what you don't use.
I used willow water for awhile when I lived in a place with a large weeping willow in front yard. Works super and I used it liberally. Must be stored in fridge so it doesn't grow unwanted stuff.
The deal with not feeding Mother plant before cutting is useful info for hard to clone strains. I got this info from a Cervantes article and it has worked for me. The idea is this: If you withhold feedings to the Mother plant a week before cutting, the plant can't make chlorophyll (due to N and Mg shortage). So because of that, sugar stacks up in the leaf, and when you take a cutting at that point...it will have maximum stored sugars and will be able to put good energy into root production and staying alive. Make sense?
It works better in hydro Mothers but I suppose soil flushing a week in advance would do the job. Never did it that way.
Cheers all,
JD