The rule you refer to is explicitly for opening or consuming a single stack of items - not autoclickers in general. Opening or consuming a stack of items is a finite sequence of inputs. Using an item endlessly without manual input is an infinite sequence of inputs.
I don't know if ANet normally tolerates the use of toggled autoclickers for the candy corn gobbler or not, but their policy on macros would forbid it. I wish they would just lower the painfully long internal cooldown on the gobbler so there would be no need for autoclicking.