never use anything to clean the silver rods but distilled water. get a new green scotch pad to clean them with or use paper towel. discoloration is just silver oxide forming, which will happen while making it anyway.
the bubbles are normal. electrolysis will divide the water into hydrogen and oxygen.
the key here is NO CONTAMINANTS. NOTHING but distilled water and pure silver should ever be part of the process. not soap residue in your container, not cleaner on your rods, not even tap water residue. if i wash the jar i make CS in, i final rinse with distilled water. be quite anal about these cleanliness procedures. i dont even like touching anything going into or holding the water with my fingers. this assures pure silver in pure water. thats the stuff that works.