I had the same problem, I developed an infection because food became trapped inside the gaping holes formerly occupied by my wisdom teeth. If you smell or taste something foul, that is a good sign you have an infection draining. Actually it wasn't so much an 'infection' as it was food particles decomposing. Nasty sh-t. I went back to the dentist and he flushed the whole area out really good.
I just had to swish warm (almost hot) salt water around back there really good after I ate and I was a lot more selective about what I ate for the next few weeks. I took really small bites instead of normal ones, chewed carefully to avoid getting food back there, and washed every bite down with a little bit of water. Seemed to help a lot.