Which tampons aren’t recommended to be in for that long?

Not all periods are created equal! It all depends on the heaviness of your flow and what absorbency you use (light, heavy etc.). The trick for knowing when to take it out, and which size to use, is how much white is left on the tampon when you're bleeding. You should be taking your tampon out at around the 6 hour mark to prevent toxic shock syndrome, or when it is full and you start to leak.