That's why there are research ethics boards - I'd be surprised if this cleared one. I can say from very similar experiences that kind of activity can damage trust and destroy relationships with people.
That reminds me of a BBC documentary called "But is it art?", where a Goldsmiths, University of London art student, for her final project, went to several art exhibitions, stole objects on display, swallowed them, and then showed them as her art after defecating them.
Source: I'm a Goldsmiths alumnus.