My latest brew has left a ring from the krausen just past the neck of my Better Bottle. I am on my third soak with a little bleach and warm water. Usually this does the trick, but I'm almost thinking at this point I may need to use something (soft) to scrub it off. Any advice for dealing with difficult deposits in a Better Bottle?
PBW. It is magic. Seriously. Put a bit in there with warm water, and the krausen should go away in 30 minutes. I once put a touch in my coffee mug, and the stains from months of not washing it diligently were erased. It's magic.
PBW is an excellent choice as PJ mentioned. I agree with him regarding it.
However, there is a cheaper alternative, albeit not as effective. You can use sodium percarbonate, or as they call in in the landry isle, Oxyclean. I use a cheap generic Oxyclean (I think I use SunPower or something like that) to clean most of my better bottles and even glass carboys. Couple of big scoops of it into hot water and soak for a few hours.
That being said, if that ring is a real problem, PBW really does the job and does it well.