The coaches that advised both Brit and Zig to "seduce" their Hs is right on, IMHO.
Unless I'm missing something (and I really haven't followed Brit's situation, at all) I couldn't DISAGREE more. If the cheating spouse has ENDED all contact with their affair partner, but still not taken any steps back towards the marriage, then yes -- by all means try to seduce them. Especially if the betrayed spouse's lower sexual drive has been a complaint in the past, and/or sex has been a problem in the marriage in general.
But if they're still actively carrying on an affair? Try to get them to have sex with you? That only enables their bad behavior (basic common sense), and I at least HOPE TO GOD that one would use protection in that situation.
Humans -- men, especially -- are path-of-least-resistance creatures. If we get to have our cake and eat it, too, and there's no "fear of loss" to motivate us, we're simply going to keep on our current path, in my experience.