In my HS classroom I had two downdraft industrial blowers. These tables with gigantic fans and four walls of filters were purchase for me to use as air filtration systems along with the large wall mounted device in the room. When I taught week long summer classes in Ceramics I would use these to force dry pieces by students ranging from 6-13. These were mostly slab constructions and coil constructions. I would force the last load on a Wednesday when they finished their pots by putting everything on the blowers for 3 hrs. Load the kiln, fire slow to 1100F. then finish up. Next morning all pieces were glazed, loaded and fired for Friday class. The downdraft blower would take a 3/8" slab 12'X12" to bone dry in 45 minutes!
Over the years of firing, and seeing blown ware on occasion, I learned that air bubbles had nothing to do with explosions. Looking at the shards from a blown pot, 90% of the time they would be sharp, small, and kind of following some sort of striation or grain in the piece. Very few times would one find a smooth edge, or pocket indicating an air pocket. I made certain to check closely how the pieces were, how far they would travel, and the type of shard they would leave. It became easy to assume in the end that the only reason for a blow up in the kiln was excess moisture, either from the piece not being dry or not coming up to 1100F. slow enough. For these reasons, I candled student work carefully, and also watched my rate of climb with the manual kilns that I used.
I used to do a project years ago where I would have students cover river rocks with slabs sealed tight, then remove the rock reassemble the slab and cut out an opening for a container adding a decorative handle or sculptural top. On occasion students insisted on not adding an opening because they wanted the rock form as sculpture. I went along, fired the pieces and they survived easily. I had not bought into the blow up of trapped air myth.