The glitch can be done anywhere where there is a magnetic ceiling.

Put the boots on the D-pad, don't put them on though. Then go under the magnetic field and put them on. When you are in mid air, push - and put an item on where the boots were on the d-pad, also make sure that the boots are not on the D-pad. Unpause the game and you should be on the ceiling without the iron boots on. You will be walking at Link's speed without the boots.

To get down, put the boots on, then take them off.