It naturally unfreezes pretty fast even if you don't do anything to it.

Another glitch I found was that in single player, if you shoot a power up, you can sometimes get more than 99 ammo. If you touch more ammo of that type, or kick/stomp/uppercut the power up, your ammo will return to 99, but you can die after you touched a save point, or save the game, and you'll have the ammo when you respawn or load the game again.

I left jazz running, and put a weight on the space bar next to the fast generating bouncer power up in Neobeo's Firetruck, and when I finally decided to stop it, I had over 20,000 ammo.