At my house the rule is "bugger off".Round our way the unwritten rule is-
Lit pumpkin/Halloween decorations = OK to knock on.
No pumpkin or decoration = don't disturb.
Same round this way.. We usually get through a couple of pounds of apples, some oranges, and a few quids worth of cheapo sweets ( a good many going southward in the direction of my tummy LOL !! )Round our way the unwritten rule is-
Lit pumpkin/Halloween decorations = OK to knock on.
No pumpkin or decoration = don't disturb.
. I ate a severed thumb earlier