I do the same as bikebryan and rinse when I empty. But if I receive old bottles or from people I'm unsure about, I'll clean them the same way as I do everything else:
I follow a simple 3-step method because, well I'm lazy. I use lye to eliminate organics, acid to eliminate stone then sanitize.
First, line a garbage can with a heavy-duty bag and put in everything you want cleaned including kegs, parts, equipment, and bottles. Fill with water and mix in lye. (This must be done in a well-ventilated area). Wait 24 hours. Empty solution into drains to keep them clean or reuse. Rinse off bottles, parts, etc.
Second, line a garbage can with a heavy-duty bag and put in everything you want cleaned including kegs, parts, equipment, and bottles. Fill with water and mix in acid. I use phosphoric acid. (This must be done in a well ventilated area and be careful because it will etch your concrete). Wait 24 hours. Empty solution into drains to keep them clean or reuse. Rinse off bottles, parts, etc.
Third, soak in Iodaphor solution for 20 minutes then drain before using. Now everything looks brand new, shiny and clean without one brush stroke. Hope that helps. Good luck.
Wild