[Healeys] Decarbonizing technique?

[R. Cobb]

Using water to decarbonize is a very old mechanic's trick.  I recall 
using it first on my 1950 GMC pickup in the early 70's.

The theory apparently is that the fluid water entering the combustion 
chamber breaks loose the carbon due to temperature 
differential/expansion as the water heats rapidly.
The method I used was to pour a cup of water into the intake of the 
carburetor, with the air filter removed while controlling the throttle 
so the engine runs fast enough to not stall as the water is added.

The only practical risk that I am aware of is that the small carbon 
particles that have broken free may get stuck beneath the valves, 
preventing them from seating fully.
Never tried it on the Healey, due to lack of apparent need.

Bob.