Would this pragmatic law greatly reduce rapes on campus and elsewhere?

Honestly, I cannot imagine any man agreeing with this. Essentially you are opening yourself up to XX days in jail just for having sex. No proof needed beyond an accusation. And if you think a college girl is above such a thing as revenge or payback, think again! No one would agree to such a thing!

As a woman, I have 2 sons: no way. This is perhaps a happy medium, but this is too important an issue to allow a happy medium to decide.

What if men could accuse resulting in an automatic jail confinement for the woman?

No. Sorry. Justice is tough, and not always fair. But that does not mean we just chuck it.