Code:
/run if not AutoTreatsPlz then local f = CreateFrame("Frame","AutoTreatsPlz") f:RegisterEvent("GOSSIP_SHOW") f:SetScript("OnEvent",function() if GetGossipOptions()=="Trick or Treat!" then SelectGossipOption(1) CloseGossip() end end) end
Paste it in the chat, this macro will make you able to do this trick but you need to paste it in each login or after a logout or DC. 
*Edit*
Some innkeepers have the "Trick or Treat" on a different location, some got it on top and others on the bottom of the list of buttons. So what you can do is use this instead:
1. Run this code in the chat frame ONCE per session (after you login, each time you relog or get DC):
Code:
/run local f=CreateFrame("Frame")f:RegisterEvent("GOSSIP_SHOW")f:SetScript("OnEvent",function()if not ATOT then return;end for i=1,9 do if select(i,GetGossipOptions())=="Trick or Treat!" then SelectGossipOption(ATOT)CloseGossip()end end end)
2. Run this code and change the value to the position of the Trick or Treat! button.
3. To disable it if you plan to travel around to some other innkeper (you need to stop the spamming so you can see the position of the button):

That's it.
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