To create feminized seed a female pollen drop must be achieved. The pollen is collected and dusted onto other female plants. This pollination will always result in feminized seeds, as the female plant will not pass on a Y chromosome. Although there are mostly female seeds, some express male traits. If not caught early one plant can pollinate many other female cannabis plants.
When you pollinate the same Phenotype of a strain that you collected the pollen from that is referred to as backcrossing, sometimes denoted as a S1. Cross pollination of different strains is referred to as a F1 Reversal and denoted as F1R.
Inducing stress results in increased gibberelin hormone production inducing pollen drop. Breeding using colloidal silver to cause stress will pass on bad traits. A properly done reversal using gibberellic acid will not pass on bad traits such as hermaphroditism, rather, Enhance clone traits.
The goal is to increase gibberelin production while decreasing ethylene production. This will create the Right Conditions for the female plants to drop pollen without stress or passing on undesirable traits. A specialized solution is diluted with water and sprayed onto the plants, that process is repeated until pollen sacks develop. A reversal is never permanent. Changing the sex of the plant is only temporary and does not alter the DNA. Once you stop spraying you have roughly 6 weeks until the plant reverts back to female.
While feminized seeds are cost effective, they guarantee near 100% female crops allowing for no male specimens to discard. Feminized seeds are not the appropriate choice if your aim is to produce seeds and Alter Genetic Strains.
Cannabis Genetics can get very convoluted on a macro scale but creating feminized seeds is relatively easy.