stress ball that sits comfortably in your hand. you can even mix rice and flour in equal parts and use it as a ball filling for more grip. for easy filling, use the funnel or quickly make a paper bag and cut out a small opening at the top.
now it’s the balloon’s turn. blow it up and attach it to the bottle opening so that you fill it with the flour when turning the bottle over.
if the whole filling is already in the balloon, then take it very carefully from the bottle opening, so that the air does not go out too fast. otherwise, the flour will be blown out 