what happens if gasoline gets inside a kiln?

It would burn for a while, but then the pressure would build up and the kiln would explode!

Obviously the explosive force of a drop will do almost nothing - probably blow the clay apart like excess water does. An amount like a quarter cup, depending on the exposure cycle (how fast it is heated and how it can evaporate) might blow the lid off the kiln. The most obvious and most dangerous risk would be if the gasoline vapor were heated above the ignition point but there wasn't enough air inside or it was used up - when the lid was opened the gasoline would erupt explosively and a 2000-3000F fire ball would char the hands and face of the person opening the kiln and probably set the walls of the room on fire

it would explode once the kiln gets hot enough to ignite the gasoline. The amount of damage would depend on the amount of gasoline.

Gasoline does not burn safely. That's why you use kerosene (paraffine oil) if you juggle torches or do fire poi.

GASOLINE, PAINT THINNER, AIRPLANE FUEL, and other highly volatile fuels are extremely explosive and extremely toxic. The fumes remaining in a one-gallon can that has been emptied of gasoline can explode with the force of a stick of dynamite. When it is very hot and humid, gasoline fumes will not readily disperse and may be ignited as much as a half hour after all the original products are capped and stored. The fumes from Coleman, lighter fluid, and barbecue starter will explode almost as readily, but not with quite the same force -- say, a half-stick of dynamite. Kerosene and lamp oil are fairly hard to blow up, which is why they are used in lamps and home heaters.

DON'T DO IT. DON'T HEAT UP THE KILN. TELL SOMEONE IN CHARGE.

It could explode and cause a fire. The explosion could destroy the room and kill people. It could start a fire and burn down the school.

DON'T DO IT. DON'T HEAT UP THE KILN. TELL SOMEONE IN CHARGE.