Why doesn't my script get rid of these guis?

So in my game, I don't want the leaderboard, health, backpack, or chat to show up. SO I use this:

game.StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.All, false)

That alone didn't work, so I tried this:

game.Players.PlayerAdded:Connect(function(plr)
	plr.CharacterAdded:Connect(function(char)
		game.StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.All, false)
	end)
end)

That didn't work either.