Rape victim jailed to ensure she’d testify against her attacker

Even without knowing what your '"1 in 5" epidemic' means, the answer is clearly no.

Some methods are not effective.

Some methods may be effective for the short-term goal of putting a given serial rapist in jail, but end up making it less likely to find others who will testify for other cases, so end up with fewer convictions, or more likely for the defendant to accuse the witness of lying in order to avoid additional harsh treatment.

Some methods are simply immoral and/or illegal: it is abhorrent to rape or threaten to rape a woman in order to get her to testify about a rape case.

This account appears to combine aspects of the last two.