If you rinse them out with warm water and some shaking, all bottles are equally as easy to sanitize and there are plenty of ways to do that. I personally put pieces of tinfoil on them, preheat them in the oven at 340, and leave them in there for just over an hour. Many ways to do it, thats just mine and I never need to scrub my bottles.
EDIT: I meant if you rinse them out right after you pour them.