How do I deal with the gunslingers on Main Street?

Hint 1 of 5:

You need to make them laugh.

Hint 2 of 5:

Give them something to take their mind off of all of their pain.

Hint 3 of 5:

Laughing gas was used by dentists to alleviate pain.

Hint 4 of 5:

Barbers in the old days used to do dental work.

Hint 5 of 5:

You need to trade the French postcards with the barber, and he'll give you
a can of laughing gas.