so I hit 24k miles this weekend and I changed the oil again and decided to take a peek at the air filter of the CAI (mazdaspeed), looked somewhat dirty (I put it on around 12k or so) used one bottle of the cleaning solution and followed procedure. It cleaned it ok but since I started late I had no time to let ir dry all day. Got a hair dryer and stuck it in there on max speed but lowest temp (dont wanna burn the plastic) and every now and again I would switch to high temp for a minute to sweat it out, Wrapping some paper towels around the airfilter and making a seal with the dryer worked best and it dried in less than an hour. that night i only gunned it once just to make sure the moisture wouldnt throw a cel my way and the car felt better. I think the recommended is like 20k but I would suggest do it every 10k and one bottle, I live in So Cal and roads are always clean.