Float cancel tomahawk grab. You can make this REALLY fast by canceling your UPWARD momentum before you hit your apex with a float.
Jump
Float before apex, I press down on stick
Let go of jump button right when I'm making the down motion
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Result: Peach goes up and down REALLY quick. This does require some finesse, if there's no fast fall, this is relatively slow.
This makes for some REALLY nice tricks if you can condition people by stuffing them with dairs. Tomahawk grabs are amazing here since against good opponents I'm not getting as many grabs as I like.
What makes this "REALLY" nice as I stated is, when you practice this, you practice it straight up and down. But when you can do this diagonally, you are essentially moving at the same velocity as the dash/float speed and they have to shield to respect your float option but you're continuing to move forward and grabbing them before they can react to this new option you haven't shown them.