This works in pretty much any American city.

If anything, you have to be careful with this in New York specifically, because some of the little boutique hotels have tiny lobbies that don't have a bathroom. Make sure to go for a big brand-name hotel.

The outer boroughs are trickier, but I've found that McDonald's and KFC generally have open bathrooms. And gas stations with attached convenience stores, which do exist in Queens.

Nice restaurants were also a good place to go because they had good customer service habits. Any bar or places that serves alcohol has to have a bathroom.

In NYC iirc, 20 seats or more and built before 1970 or so also required it. I looked this up once after getting sick of being told there was no bathroom at places that seemed likely to be lying.

I tried to sneak in a restaurant to use the bathroom but couldn’t. I used a bathroom in a bar once.

Your mistake was acting sneaky.

Also some restaurants say “customers only”.

As a tourist, I didn’t know this. Will try this next time. I was wondering if I should pay tips or not in that case.

Unless there’s a bathroom attendant you’re just ignored. Tips wouldn’t be necessary.

That also works well in San Francisco.

Really? Should I call it as Pee Francisco?