What your friend is reffering too is the bio bb's from the past. The ones that chipped, powdered, and as you said, broke down really fast and potentially gummed up your guns or mags.
BIO bb's have come a long way since then, they are more reliable, accurate, and take longer to break down, even when subjected to water right away. The old BIO's have left a sour taste in a lot of peoples mouths, and understandably so..
Our Bastard BIO's have been given nothing but good support from those who have used them, and all of the potential problems you have listed, has never been reported.