You can shorten the drying of an air dry clay piece by perhaps a third without much risk, and you can ruin it in an afternoon by doing the obvious thing. The safe lever is airflow. The unsafe one is heat, because heat dries the surface faster than water can travel out of the core, which is exactly the condition that cracks clay.
Move air, do not add heat
A fan set on low in the same room, not pointed straight at the piece, dries a form noticeably faster than still air and does it evenly because it lifts humidity away from every surface at a similar rate. A hairdryer, an oven or a radiator does the opposite: it drives one face of the clay well ahead of the rest, and the finished piece either cracks along the join between fast and slow, or warps as one side shrinks first.
Change the shape before you change the schedule
The largest single gain is not a drying trick at all. Hollowing a thick form, or building it hollow in the first place, halves the distance water has to travel and can turn five days into two. Thinning the base of a solid piece has the same effect. Both are done while the clay is still workable, which means the decision about drying speed is really made at the making stage.
Turn it, and give the underside a chance
A piece sitting flat on a table dries from every surface except the one that matters most, and the trapped base stays wet long after the top is ready. Stand it on a wire rack, a piece of scrap wood with battens, or simply turn it over once a day. This costs nothing and is the difference between an evenly dry piece and one that cracks around the foot.
What not to do, with the reason
Do not put it in an oven, even on the lowest setting; do not use a heat gun; do not leave it on a sunny windowsill. All three produce the same failure and it usually appears a day later as a crack running through the thickest section. If a deadline genuinely requires a piece dry tomorrow, the answer is to make it thinner today rather than hotter tonight.
Questions people ask about air dry clay
Can I use a hairdryer on air dry clay?
You can, and it is the most reliable way to crack a piece. It dries one face far ahead of the interior. Use a fan in the room instead if you need to speed things up.
How much faster can it safely go?
Roughly a third quicker with good airflow and turning. Beyond that you are trading a finished piece for a cracked one.
Will a dehumidifier help?
Yes, and gently, because it lowers humidity everywhere in the room rather than blasting one surface. It is the closest thing to a safe accelerator.