How can I get the dunny man's gold?

Hint 1 of 10:

Take a look at his mouth.

Hint 2 of 10:

You'll want to take his gold tooth.

Hint 3 of 10:

The only person qualified to remove it is a dentist (or the equivalent for
this time period).  Perhaps you should try to convince him to go see one.

Hint 4 of 10:

Look for something "edible" that might damage his teeth.

Hint 5 of 10:

The donuts that the dibbler is selling will work.  Just talk to the dibbler
to get one.

Hint 6 of 10:

Then give the donut to the dunny man.  He'll go running to the barber.