I'd do it, too
(but no BBQ - I'll leave that for the southerners!)
Jo, if you want to do it, do it. The things you should think about, other
than what Mils said, are having at least 2 spaces, like a therapists office,
where people wait in one room, and the second office space has a
back door clients can leave by for their privacy. You might want to consider
soundproofing. If you just rented out a hotel room, the noise levels may
eventually cause you to be denied their service. Or even an office space.
And doing it in your home is not practical for many, many reasons. I'm
sure you can come up with those on your own.
Whether you specialise in tickling only and come into NYC 1-2 days a week
with pre-set appointments, or you find a local space to rent, you'll want
to make sure that your income far outweighs the expenses, and if you need
a bodyguard, to include that cost as well.
Lee