We don't use water bottles for this very reason- most of them leak. We've bought the expensive kinds before where you can open the top and pour watter into the bottle, but this bottle also leaks. Instead we just use bowls for food and water. Yes, the water bowls get dirty awfully quick from the cedar shavings, and cavy "poo," but this seems to work better than bottles. The bowls don't leak! We clean the food dishes once per day, and the water bowls 1-2 times a day. It's a big job, but this is all part of taking care of 17 cavies!
Christopher