Water Temple BK Skip with Hammer

This trick is relatively precise and utilizes a mechanic that I don't think many OoT players know, or if they do, it's not common enough knowledge to reach those of us who don't use it that often.  That piece of knowledge is that holding down when doing chu hovers matters.  If you're holding before dropping the chu, and through the backflip, you move backwards ever so slightly more than if you flicked.  Because this trick requires you to be SO close to the door so as to not hit with the hammer, over the course of 3 chu hovers, this adds up.  So... here's what you do:

1) Set up the hover as usual, but be sure on the initial hovers that each is a hover within 3 frames of perfect.  You can tell by where link "stop" midair.  If he's upside-down completely, that's a perfect hover, the next two frame work for both initials, I'm pretty sure.

2) Do 3 chu hovers, being sure to not hold down during them, as stated above

3) Hold left/right and pull the hammer.  Keep holding left/right and then switch to up-left/up-right (same orientation as the direction you chose before), and press A on the same frame.  This will cause a jumpslash that drifts slightly to the side and forward, giving the leniency on the initial hovers.

I believe that even if both initial hovers are perfect, holding down on the chu hovers will still ruin it.

Backup:
Because you can see both initial hovers very well, you'll know whether the trick will potentially work or not immediately.  If you have bad initial hovers, you can save it.  Do the chu hovers as you normally would, holding down if you like, then set up a forward sidehop.  Unequip hovers, and pause on the first frame of the forward sidehop.  Out of this unpause lag, mash hammer and keep holding up.  You should jumpslash through the door.  I think this is a 2 frame window on the jumpslash.