In the Season 12 episode "Peanuts" (S12, ep 17, aired Feb. 1972), Ernie arrives with a huge bag of raw peanuts he's just purchased. Charley asks him why he's acquired that, and Ernie explains that the peanuts will be sold at Dodie's school as a fundraiser (after roasting).
Immediately Barbara comes in and asks where Dodie is. And
right away, Charley replies that Dodie is
out buying sacks (bags).
So Charley knew that Dodie was buying sacks
BEFORE Ernie arrived with the peanuts in bulk. Yet he was totally clueless about the raw peanuts. It seems to be a script error in that Charley had let Dodie go and purchase sacks -- without asking Dodie (or Barbara)
why she needed them (what they would be used for)...!
Unless there was a small scene edited-out from the print we've seen, which there doesn't seem to be room for, this seems like a script error.