I used to have HKS power flow. So it happened that the sponge went reput liao so I changed temporarily to a normal sponge (very soft one), I think it is used for cuci pinggan one. That night I revved my car like crazy forgot about the sponge. Suddenly while happy revving, the car wont stop revving after I lifted the gas pedal. Then oni I remembered about the sponge. Quickly I put the gear to N and pulled over to the side of the road. PPl must have thought that I went crazy revving the car at 6k++ rpm while the car going oni at 10km/h and stopped eventually. Switched off the engine and took out the air-ram, and there ...... some sponge nicely squished at the bottom part of the butterfly opening at my throttle body. Lucky it didnt stuck inside the intake manifold. Took out the sponge and went home without sponge (now that's what I called OPEN pod) hehe.
The next day went to accesory shop and got myself an imitation power flow, took out the sponge and put it in my HKS. It worked fine all the way till I finally changed to an Apexi immitation air filter. No more headache about changing sponge liao.
Moral of the story: Use sponge accordingly! If it's meant for cuci pinggan then cuci pinggan it is for :)