I think what we need is to encourage people in this forum, Discord, etc., to share what good and services they can provide for ZEC payment.
Convinced you barber to take ZEC? Tell us! Maybe someone is in the area and can use their ZEC.
An idea that I have discussed with some people is that events like Zcon (when in person) could have a “vendor afternoon” where local vendors can set up their stand to sell stuff to the attendants of the event. If they agree to take ZEC, they can do it for free, otherwise they pay a fee.
If you want to start the freewheel, you need both a reasonable amount of people with ZEC (willing to spend it) and a variety of vendors willing to accept it.
When the Zcon-like event is over, it would leave behind a bunch of vendors that take ZEC in that location.