1st Method:

Y = hookmetamethod(game,"__namecall",function(self,...)
  local args = {...};
  local checkargs = {};
  local method = getnamecallmethod()
  local last
  if method == "Fire" or method == "FireServer" then
      if self.Name == "MessagePosted" or self.Name == "SayMessageRequest"   then
            last = args[1]
            --print(args[1].. last)
             if last == args[1] then
             return  Y(self,...)
               else
                  return
                  end
              if method == "ReportAbuse" and self == game.Players.LocalPlayer then
                  return
         end
      end
  end
  return Y(self,...)
end)


Second method:


if not game:IsLoaded() then
   game.Loaded:Wait()
end

if game.PlaceId ~= 7056922815 then
if game.PlaceId ~= 4991214437 then
if game.PlaceId ~= 7298553006 then
if game.PlaceId ~= 8934886191 then
if game.PlaceId ~= 6494527314 then
local LP = game:GetService('Players').LocalPlayer
local PlayerScripts = LP ~= nil and LP:FindFirstChild('PlayerScripts') or nil
local ChatScript = PlayerScripts ~= nil and PlayerScripts:FindFirstChild('ChatScript') or nil
local ChatMain = ChatScript ~= nil and ChatScript:FindFirstChild('ChatMain') or nil

if LP and ChatMain ~= nil then
   local Old, Chatted, OldChatted = nil, Instance.new('BindableEvent'), LP.Chatted; Chatted.Name = LP.Name..'_Chatted_Event'
   Old = hookmetamethod(game, '__index', newcclosure(function(self, Index)
       if checkcaller() and self == LP and Index == 'Chatted' then
           return Chatted.Event
       elseif not checkcaller() and self == LP and Index == 'Chatted' then
           return OldChatted
       end

       return Old(self, Index)
   end))

   local Old2, MessagePosted = nil, require(ChatMain).MessagePosted
   if MessagePosted ~= "sakanade" then
       Old2 = hookfunction(MessagePosted.fire, function(self, ...)
           if not checkcaller() then
print(self, ...)
               return Chatted:Fire(...)
           end
       end)
   end
end
end
end
end
end
end


3rd Method (Removes Chat)

local StarterGui = game:GetService('StarterGui')

StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Chat, false)