I don't think OW get subtle hints do you? If H says it's over and yet still has these long conversations with her, don't you think SHE will still think that there is hope for "them"? My H's OW has her claws in deep. When he tried to break it off with her a couple of times before, she always "talked" her way back into his (our!) life. Just goes to show you that HE wasn't serious about ending it. I just told him to not even act like he's cutting ties with her unless he's serious about no contact at all..
It's so darn hard to be in your situation. You want to openly rejoice but you still have to be guarded. Good for you for giving him a deadline. Hang in there.. take it slow..