I discovered last night during a bottling session that my previous routine of rinsing a bottle out after opening a beer is woefully inadequate. I started inspecting the bottles with a light and half of them were still very dirty. They had a film that covered the inside, a ring at the top, yeast spots, or all 3. Mind you I have been reusing these bottles for years and entering, and winning many competitions with beers in these bottles. I am surprised all the beers were not infected. Most of them were higher alcohol Belgian beers so maybe that helped keep infection down.
After coming to this revelation last night I proceeded to put hot PBW in each bottle, shake it vigorously, then clean it with a bottle brush before rinsing it and giving it a few sanitzer quirts (from my bottle tree attachment). So, at least the two batches of beer I bottled last night a were in nice clean bottles.