Look, if you do this and it brings you joy - keep doing it! But, if you've been wanting to try it? I'm here to tell you to bring your sharpest knife and strongest muscles & have the ER on speed dial because you may cut yourself. Those things are hard as crap to cut! (And zero videos I watched showed that) And also, they don't fit super well on a lot of cups! I tried 3 cups and the straw barely fit out the top. I'm of the opinion it ain't worth the effort (or potential stitches 😉) because my kids drink their water just fine without 🤣🤷🏽‍♀️ But, I still LOVE this Good2Grow bottles! My kids like using them on trips or getting them as rewards & I love reusing them because that no spill technology is 👌🏻 LTKFamily LTKKids