Glad the swelling has gone down and yes, it will take several weeks to get good control - after 10 weeks or so I am about 95% - sneezing still causes a dribble but nighttime is dry and just one pad during the day.
He needs to practice the kegal exercises and stop/start his pee flow when urinating. It just takes time and get him to go to the loo regularly and not leave it to the last second.
Pee flow might be slow for a week or so while the sutures heal and he might pass bits of 'debris' occasionally - all perfectly normal.
If he doesn't feel that it is improving after a couple of weeks, then seek out a physiotherapist who deals with incontinence as they can help ensure he is working the correct muscles.
Good luck