No, not literally on a leash.
I limit my Dh's video game time. He would play it all day if I let him and I won't. When he gets a new game he gets maybe an hour or so of playing before I make him turn it off.
When my husband interacts with a "friend" that I feel is poisonous to our marriage or family, I cut that friend off and Dh doesn't interact with him anymore. I've gone so far as to delete this friend from his facebook, delete all messages from this friend off his FB and phone, and delete and block this friend from his phone.
When I get home from work with Dd and Dh is working on something like his car or whathaveyou I have him put it away and come inside the house to be with us.
Dh and I have to agree before he goes out and does something that requires him to be gone all day and if we don't agree then he doesn't do it.
Dh has specific chores that are just for him and he's expected to do them.
We agree on everything before spending money on it and that includes stuff he wants. If we don't agree, he doesn't get to have it. The end.
There you go! Bash away, ask me anything, praise me, share your own stories, etc etc. We've been married for years.