Firstly, using CS stops the female hormone production at the genetic level, i.e., blocks the genetic expression that calls for that to happen so the plant produces pollen on the branches that were sprayed, the other branches will produce reg flowers and will not be effected.
If you dust those flowers (or flowers on another plant) with the pollen collected from the treated branch it will/should produce seed. You could collect the seeds and smoke the left over buds if you wish, it isn't harmfull as they were not treated. The branch that produces pollen will not make buds like a female plant does so you wouldn't have anything to smoke from those anyways. How it produces female seeds is rather simple....since the plant that gets treated is geneticly a female it doesn't have the genetic code of the male to pass on, theoreticly. There are instances that a male plant will be produced at times. I have some Purple Deisel seeds I made this way out there that have produced a couple of male plants but the majority are female.
I don't know what harmfull effects you would get from smoking it if you wanted to though, people are known to drink the stuff for medical benefits as it's said to detoxify the body. There would be much less taken in from smoking than drinking the solution on a daily basis. Some people consume so much that thier skin turns blue and there is a video on youtube of such a person. Sorry, I don't have the link. Also, you spray the leaves not the buds and only for the first few weeks of the cycle. If the buds that develope later because the CS didn't take should have a much more diluted amount of CS and should probably be OK. I would stay away from the leaves that it has been applied to and just throw them away.
Myself, I would stay away from it, I like my sex parts the way they are, thank you very much! LOLOL When I'm making seed this way, it is planned for seed making and that's all. I have other plants going at the time for my personal smoke.