Timeouts don't work either

This avoids the problem.

physically restraining him

This exacerbates the problem. How can anyone trust someone who physically ties them down? Can you start any kind of relationship like this, let alone continue one with your parent? One cannot respond to emotional abuse and physical abuse with emotional abuse and physical abuse, and expect the relationship to improve.

natural consequences

Googling this.

    Natural consequences are the inevitable result of a child's 
    own actions. For example, despite Dad's urging him to put on
    his coat, Tommy goes outside when it's cold without wearing a 
    coat. The natural result is that Tommy gets cold.

If you mean he wouldn't wear a coat even if it's cold, and ignores the cold, then by all means let him continue.

get angrier and call you names.

How do you feel when he is angry and call you names? Not the "parent armor" that you wear. Turn that off, turn off the "I'm doing this for your own good", turn off the "I'm parent so I can tell you what to do". But how do you, the child inside you, the one who feel secure in the love of your parents, feel inside? Let that child out. If you're going to cry and stay at home in bed all day hiding because you can't handle the emotions, then do that.

That's natural consequence.

Avoid raising your voice, avoid coercing him to do your wish, avoid tieing him down. If he would stay at home than go with you to picnic, trust him, and let you or your wife stay at home to make sure he is safe, while the rest of the family continue on. Let him physically hurt you (but not your wife or other children), unless your life is in danger.

The fact that you put natural consequence in quotes, shows you can respect it a little more.

EDIT; But it is very good you are asking for help, it is on the path to becoming a good father.