no, air doesn't do it. water does. water expands as it heats. if you are in doubt about the dryness of a piece, just put it in your kiln and set the controls to preheat. you can choose the length of time to preheat but my kiln rep says that the speed of getting it up to boiling, 212 degrees is so slow that the hold time of 15 minutes is enough. i assume you are not trying to fire a brick thick item or a bowling ball.
if you really worry about that piece that exploded, look at closely and see if you can see how thick it was. new throwers make very thick bottoms without realizing it. when you start throwing, cut the pots in half downward and check the thickness. remember that when you are starting out you are learning a skill, not making a product. cut down ten or so and get familiar with the feeling of the thickness. don't get hung up on making something until you can do it well.