Joy, if you haven't, you should read his paper at
www.lulu.com! It's
really quite lovely, and as I recall lays out his reasons very well.
In recent posts (can't remember if you were on the list at the time,
tho) he's described his observations re deeper, faster action of the
potencies used in this way. THe paper explains his theories about why
that might be. Quite a wonderful paper!