This is a problem that I am very concerned about for myself, as I have always wolfed and washed my food down.
I figure practice makes perfect (not banded yet, 44 days but who's counting), so every time I eat I try to take smaller bites, and I force myself to chew every bite 33 times. I usually don't make it past 16-20 chews, as the food has pretty much dissolved by then, but I find if I keep that 33 number in my mind, I am counting my chews and slowing down. And no beverages with food REALLY helps, as I can't wash it down.
Another plus side to this - I have discovered flavors I didn't know existed in the foods I eat! Never before did I realize that oatmeal had such depth...