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That doesn't work very well on a humid day outside in the summer.

And the payphones in the city I grew up in didn't operate using ground-start signalling, so the paper clip/safety pin/pull-tab/static trick didn't work there at all.

But an innocuous walkman with a cassette tape that had some red box tones on it, with a bonus of having the rest of the cassette available for music to listen to? That worked great.

[jibal]

This was in the late 1950's for me, in the San Fernando Valley where summertime humidity was very low. But a few years later the phone company put shields in the headsets so you could no longer puncture the foil.

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Fair.

I'm old enough to remember payphones being completely ubiquitous (with whole banks of them inside of each entrance for one large department store, usually with one or two more outside), but I'm not old enough to remember the 1950s. :)

I did find one old phone at a state park not too far out that could be tricked by grounding it, but that was in GTE territory instead of the Ohio Bell BOC that I was more familiar with.