I am/was also confused about this. Several books recommend abstinence for a agreed period.
I read the books after we had already made love quite a bit following the discovery of his PA. My husband also is not a SA but only to P and MB.
We have sex much more often then before the discovery because he no longer relieves himself. It has worked for us. My husband is now on day 85 of being completely free of P & MB.
I am interested in seeing the responses to your question
C