I think you'd need to start somewhere like the Edinburgh Festival, where all the street performers seem to actively want their photo taken. I haven't actually been there myself, so maybe I'm over-simplyfying what's involved.
I've gone to the street part of the Festival for years, and have got a few nice candid shots, although generally performers don't stop moving, so I usually find I've taken something other than what I wanted. Also, it's difficult to get a good position given other audience members who have as much right (or more right if they arrived earlier) to be in the spot you want.
One time I asked a performer permission (and paid up to his busking bowl), and he suddenly grinned and stuck his thumb up at the very last second just as the shutter was firing. Not at all what I wanted!
I have wondered about taking my Chroma, setting up in the street and waiting to see what would happen. In my dreams people come up and say "hey, what's that, cool, can you take my photo?". In reality even if they did they'd fade away before I even got the ground glass focused, let alone worked out metering, depth of field, etc etc!
However, I do know that
@thedarkshed was at Leamington Art in the Park last weekend, and used his Chroma to take paper negative shots (at ISO 6!) of willing volunteers. Of course he does actually know what he's doing! (I meant to ask him how the paper negatives converted to the positive versions I later saw on twitter, but forgot...)