This statement by Pound is pretty common knowledge to Pound/Eliot stdents:

Pound edited even the critical prose of his pupil. On one occasion,
disturbed upon reading some ill-tempered commentary by the usually moderate
Eliot, Pound admonished him. "That's not your style
at all," clucked Pound. "You let me throw the bricks through the front
window. You go in at the back door and take out the swag."

The above is from:

So where can one find the documented source for this iimportant staement.
I thought it was a Pound problem, so I asked the Pound list, but the best I
get was that it was something heard and reported by Hugh Kenner, but nobody
seems to know where he recorded it. Does anyone here know?