OK heres a down and dirty dirt simple trick for forcing many key in knob type locksets. Get a large strap wrench. What's a strap wrench? What the f*ck do you mean what's a strap wrench? How in the hell can your dumb ass not know that? OK just f****ng with you. Here's a strap wrench:
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Now take the strap wrench and fit it over the knob and put plenty of force on it. Yeah I know you're saying duh really? Yes really. There are people like Evan the maintenance moron turned college student on this forum who will say I am full of it if I don't post all the damn details. Most knobs will give to this trick, turning and retracting the latch. Yes this destroys the lock. Who cares? When you want in you want in. Vise grips and pliers will sometimes work but they tend to slip. The strap wrench will really grip and exert full force on the knob. So will your knob locks stand up to this little trick? I doubt it.
SSA