[Healeys] Decarbonizing technique?

[Awgertoo at aol.com]

I heard this from an LBC oldtimer today:  Pouring a cup or so of water  
through each carb while the engine is running is a good way of cleaning out the 
 combustion chambers.  I have never heard of this and were the fellow who  
told it to me not so experienced I would have dismissed it out of hand.
 
So, has anyone ever run across this technique and does it work?
 
Best--Michael Oritt