Well I don't think you have to go out and sleep with someone....
IMO--I look at detaching, as saying I let you go to pursue your own choices as an individual --and of course I will as well is implied (do not have to say or it sounds like a threat or ultimatum)
If you can posture with great self confidence and no ill feelings just boundaries with the other person, I think it sends the message. IMO and others here are more experts than me.
Look, if she does not come back then it will not happen. And if she does come back it will be because you were able to truly detach.... and then she has to work to get back.
H (me) 52, W 42 M 15 D14, S12 PA June and Sept 2016 Found out Sept, confronted Oct NC with OM since Oct, remorseful Dating since Nov