Hi nachoba and Lars,
Yes, I used the Gleason book as well and it's excellent, but I had started out originally with Stainer. Here's the thing--there is more than one kind of pedal technique, and you could roughly group them into old and new, kind of like early fingerings and modern fingering. Gleason is very definately modern pedal technique--heals together or knees together, play on the inside of your foot, use heels where you can, don't move your knees up and down. This works well on a concave, radiating pedalboard. The older technique works kind of like this: don't keep your knees together, play on both the inside and outside of your feet, use heels only as a last resort, learn to cross one foot in front of or behind the other in order to use toes, and let your knees move up and down as you play. Very different techniques.
Stainer leans more to the old technique, but also somewhat towards modern. I had originally learned from Stainer, with all the foot crossing, and all toe playing. But then a later teacher told me that was wrong, and I had to learn from the Gleason book, which I did. Nowadays, I know that the old technique is not wrong or bad, and it works better than modern on a flat pedalboard, so I use both techniques, whichever works the best for the instrument and music at hand. It also is nearly impossible to get the minute kind of articulation control with heels when you're playing using early technique. Toes just work better for that kind of playing. I know for those used to modern pedalboards and modern technique it may sound unreal, but the honest truth is that I prefer flat pedalboards and old technique, but I can do both.
Ok, now here's the Stainer "feeling" technique I was talking about. Right away when I was first learning to play the pedals, I also worked with a series of exercises from the Stainer book where you learn to put your toes in the spaces between groups of black notes. This has two purposes that I can determine. First, suppose, for instance, you have to play a low G, and it's an unfamiliar pedalboard where the notes are all off to the side by one or a few notes. (This is what I was talking about--pedalboards where the notes are not at all where they should be.) Well, you know the general vicinity, and then you find the b-flat key by feeling the space between black notes between b-flat and c-sharp. Once you find that space, it's an easy thing to locate G from there, no matter how weird the pedalboard is, and I've played some pretty weird early American ones where, for instance, the pedal note G lines up under the manual note C.
The other use I have for this technique is when I have to pivot or move in order to play very high pedal notes. I just find b-flat or e-flat and push. Then find f-sharp to push back into usual position.
I know these are not the usual modern pedal techniques, but I feel it's important (at least for me) to know and understand older ones so I have an idea what Bach was actually doing, though we have no record of his own pedal technique. I am just starting a study of old organ method books, and have already done some reading of early 19th century ones that show technique very different from modern. All in all, this is a fascinating study for me.
The one thing I'd say to keep in mind is that no matter how much we were forced to accept that the only correct way to play pedals is on the inside of the foot, never move the knees up and down, keep them together as much as possible . . . it's just not true. I can play an elegantly articulated pedal scale with one foot, no heels. But you have to use both inside and outside of the foot. Well, actually you can do it with just one part of the toe if you're really articulating. One 19th century method book I am examining actually has exercises for learning to use the toe of one foot to hop a fifth and keep it as connected as possible. This was not uncommon. Interesting, huh?