Sinclair's goal is to save his marriage and grow his marriage. Your advice to him doesn't include that strategy.
He is not in the 'last resort technique', he definitely not in the 'after the last resort technique' which is pretty much what you are suggesting.
And p. 213-214: (section talking about changes you'd like to see in your marriage.)
"Go slowly. You have a lot of time to get to know each other again. You don't have to tackle every concern in a one-houjr discussion. Take your time. Proceed lovingly.
If both of you follow the advice outlined and ignore friends and relatives who ask, "Why do you put up with that" or I can't believe s/he hasn't gotten over this yet," you will start to feel that your marriage is moving in the right direction."...
Michele goes on to say, then jump to Chapter 8---Keeping the Positive Changes Going. and then...to page 161, in the example she gives.....
"...I continued to work on the business and to employ the simple, unconditional frienship that has always been an ally in my relationship with my wife."
And then there's more exampls in Chapter 9, "Pulling it All Together".
Hang in there, sinclair. You can have a great marriage.