Welcome! I laughed to myself reading your post as many people, including myself, have gone backwards from heavy and specifically purchased items, to light and cheap alternatives like visqueen ground cloths, sports drink bottles instead of canteens and nalgene, cat can stoves, etc... That cup could really work well as a pot. Double points earned for multi-purpose items! I can't imagine anyone worrying about someone filtering from a water source, is there some reason you say that?