What I have discovered is that if the switches are already dirty, cleaning won't do much to restore them. Canned air is fine to blow the dust out.
However, I also discovered that with the black Alps, at least in my earlier At-101 (pre windows key, "early" black Alps), taking out the click leaf results in a linear switch superior to Green Alps on a good day.
Feels like Bentley level luxury (imagine if key switches contained air hydraulics) despite the mildly disgusting yellowing of the board. I will never give it away or sell it. (The perceived value would be too low anyway. If many people knew how good it felt, I have no doubt that they would be will to pay much more than current value).