Since pretty much everyone will find the waiting period of 2-3 months after switching it off an annoyance and possibly a deal breaker. Can’t you implement a method to inject a spermicide into the ducts which kills the remaining sperm cells after the switch has been turned off, basically making it an instant off switch without the waiting and testing?
Ok, this seems to have a some logic just after the implantation. You close the switch and through the chemicals you are infertile. But what happens if you want to open the switch again? You have to get another injection? Are these chemicals really save? 100%? Too many questions and therefore we do not think, that this proposal is the right way. Just use condoms for a few months and everything is fine. Thanks anyway.