Yeap, that can be done, there's a technique with a couple of wooden planks to support the rim and you use your feet to bend the rim back into place..... you start off with the weight on your heels and gradually roll your weiht forward and so on.I once slipped when pushing the bike up a grassy mound to look at a memorial to air ambulance on N.Uist.
Tacoed the back wheel when I landed on it. Unridable as it was I took it out of the frame and stood on the rim to push it back into kind of proper shape. Not perfect but it did me for the rest of my holiday until I got round to doing a better job on it. Went on for many miles after that with no problem.