Gas Bags -
Boeing had a permitted procedure for spraying water in what they described as a fine mist above the brakes and allowing it to settle on them.What you are supposed to use to produce this 'fine mist' I have no idea. Worst case I witnessed was in Bangkok where local mechanics were pouring water from water cooler containers onto the brakes of our 747 producing large volumes of steam and creaking noises. That was how I found out why we had so many cracked wheels - it did not happen again.