I rinse until all the residue is gone too. My boil was, hopefully, to sanitize. I'm just trying stuff to see what works and what is easiest. I got myself an 8gal boil pot and a wort chiller for practically nothing so I'm feeling pretty good about building a bottle cleaner using the aquarium pump and some copper tubing. I'd fill the sink with warm water and sanitizer and just let the bottles rinse until they are clean; Recycling water etc.