[Waverian]

local function intox(frame, event, msg, ...)
    for i=1,4 do
        if msg:match("DRUNK_MESSAGE_ITEM_OTHER"..i) then
            msg:gsub("%%s", ".*")
        elseif msg:match("DRUNK_MESSAGE_OTHER"..i) then
            msg:gsub("%%s", ".*")
        end
    end
end
ChatFrame_AddMessageEventFilter("CHAT_MSG_SYSTEM", intox)

Few problems:

* In a message event filter, you return true to filter the message completely, return false to let it pass unaltered, or return a modified string and the vararg to modify the message.

* The DRUNK_MESSAGE_ITEM_OTHERN and DRUNK_MESSAGE_OTHERN are global variables. You're just comparing your message to a direct string called DRUNK_MESSAGE_ITEM_OTHERN, etc. You want to access the variable.

local function intox(frame, event, msg, ...)
	for i=1,4 do
		-- access the global variable
		if msg:match(_G["DRUNK_MESSAGE_ITEM_OTHER"..i]) or msg:match(_G["DRUNK_MESSAGE_OTHER"..i]) then
			return true
		end
	end
	return false -- this is probably implied and not needed
end
ChatFrame_AddMessageEventFilter("CHAT_MSG_SYSTEM", intox)

Something like that, ish.