Why don’t use feminised seeds for breeding?
They have been produced by stressing female plant to produce male flowers and resulting (female) pollen was used to pollinate itself. This plant is missing part of genetics information, because it has only female genetics. Seed producers are using Colloidal Silver or other substance to induce stress and make female plant produce male flowers. Plants from feminised seeds sometimes produce male flowers and are not so stable as plants from regular seeds. This unstability leads to hermaphrodity.
Why don’t use hermaphrodites for breeding?
Remeber that you don’t want hermaphrodites in your garden. If you see a male flower in a female don’t let that plant breed (this happens with regular seeds too). This pollen sometimes produced by hermie females will create all females but the percent of hermies will increase and pollute your garden with worthless seeds. Never allow a hermie in anything but a very small garden and never breed them. Remember to remove unwanted males from the flowering room before your breeding program ruins your whole crop.
How to pollinate?
When you selectively pollinate a plant remove it from the area to do so. Place about the least amount of pollen you can imagine on your finger (or brush) and pollinate the stem pistils and a couple lower buds only. You will usually get too many seeds and the pollen can spread around so use it very sparingly. Everyone uses too much the first time so take it easy.
Let the partially pollinated plant stay out of the room for a day then shake it a bit and return it to flower room. You can rinse the pollinated plant with water to further reduce the risk of pollen spreading to other plants. A separated seeded plant area is ideal but not mandatory. Of course pro breeders have hermetically sealed separate chambers for each of seeded plants so that pollen cannot spread from one plant to another and contaminate other crosses. They basically have one cross in each chamber.
Making seeds requires a lot of the plants energy and if you want a lots of seeds you have to wait a bit longer in flowering and pollinate fully. Fully pollinated plant can produce about 10.000 seeds if it is healthy bush so be sure you really want it :).
Seeds storage
Your seeds will last a couple years at least but as the time passed the germination rates will decrease. I’ve succesfully kept my seeds at sealed container and frozen in a fridge for many years. Also germination rate doesn’t affect the genetics in any way.