Water on hammers

[Brad Smith]

While at the Piano Disc training, Don Dusenberry talked about softening
hammers with a mixture of water/alcohol.  I forget the combination. I
asked another technician about this and he said that not all types of
hammers respond the same to water. He specifically mentioned that you
might think twice about using it on an Asian hammer. (Hot pressed?)
My experience was that it was very hard to control the amount of
softening I got. True, in the case of Piano Disc, we were after major
softening for certain situations. 
What about the discussion of using steam?  (I saw it in the archives.)

Brad Smith, RPT
Manchester, NH