Stir paper cup / new type of paper cup

We can drink powder drink just with a paper cup. We can't find a muddler just to drink instant coffee anymore. Stirr paper cup is convenient. It's only made by engraving two lines on the traditional paper cup when producting. When we need a muddler, we can just slit the piece of paper, which under the paper cup, alone the dotted line. Then we could fold the piece of paper along the intermediate line. Now we get a muddler.