Help, my hamsters doesn't know how to use water bottle?

If your that worried then put a water dish in there but make sure its swallow enough for them to get out so they don't drown but they'll drink from the water bottle when their thirsty. Toilet paper roll or paper towel roll makes a good toy make sure they won't get stuck in it though. They like nesting so throw in some none ink paper or paper towels for them to nest with or cotton .