JL Hudson Seedsman has a great catalog of seeds, some rare, some(many) ethnobotanicals and also is a source of GA-3
That being said, I tried using it to induce male flowers on a female and got some bizarre stem growth instead.
Don't remember the actual strength and application rates but I went by the book.
Not happy with the stem elongation on the sprouted seeds either. Truly a last resort in my book.
My EFG offers some promise for hard-to-sprouts, other than some early, aggressive flowering on one, my two surviving females are doing quite well.
75% germ rate on 10yr refrigerator stored seed. Single test.
My next experiment with hard-to-sprouts will be with auxin rich willow twig tea.
I've had some success with it as a rooting aid, especially with woody stemmed plants.