OK, exhusband is different. Set up a time to talk to him when you will both be calm and unstressed and meet in a neutral place.
Pull together what you are going to say in advance. Try to avoid anger triggers such as “You statements”. For example, “You never get a second date because you use these phony lines.” Not good.
Instead, start by telling him that you want him to find someone and be happy. Then say that your have some feedback that might help him re-enter the dating world, but only if he wants to hear it and if you both agree in advance not to stray off topic and not to get angry.
If he says yes, phrase it in non-threatening ways so that he does not get defensive. Say something like:
“I have noticed that when you meet someone new, you use a pickup line rather than being your charming self.”
“Women are charmed by men who ask them about themselves and really listen to them. Letting your date talk first makes it easier to pick up a cue on something the two of you may have in common.”
“Women like guys who takes thing slow at the beginning.”
You get my drift. Whatever the advice is you really want to give.
Another successful technique is to start by telling him about awkwardness when you started dating and how you overcame it.
Good luck.