If they are used, and if they don't break, etc.

Sadly, among wealthy and famous men, there are even cases where the woman uses the contents of the used condom to impregnate herself - and then successfully sues for child support.

Like female BC, this is something that is completely invisible and does not rely on an external or mechanical method of prevention.

That sound more like urban legend, I would be surprised if pregnancy like that would even be possible. Anyway, you should use condom during random sex encounters due to risk std anyway. Nothing wrong with combining them with something else, absolutely do it. But this new contraceptive wont prevent std whether hiv or syphilis.

You've never heard of people relying on withdrawal? It was still pretty popular when I was in college three years ago, usually when the woman got nasty side effects from hormonal BC.

That tends to end up in big families. It is the least dependable protection.

It's slightly worse than condoms at around 96% per year vs 98% per year.

Hormonal BC is 99.9% in comparison but is not in the man's control :(