Ffs the main power of their space witches is to use a sexy voice. Which everyone knows about! Just put in earplugs or jerk off prior or get gay guys or use deaf people or get straight women before dealing with one.

Not only is there nothing in any the books to even suggest that this is the mechanism by which the Voice works, there is a very prominent scene where the main male character uses the Voice to compel other male characters to do his bidding.

(In fact, in the later books a "corrupt" version of the Bene Gesserit shows up that does explicitly use their sexuality as the source of their manipulation power, and the Bene Gesserit find this absolutely abhorrent.)