Hey Stovens: I had never heard of that though I have done that before just to clean up the inside of the motor.
But after I had torn down my holley I found I found what looked like oil in it so I stopped putting it in the tank.
So I started putting a can of trany fluid in a gallon bottle then filling it the rest of the way with water.
I would let that trickle strait down in to the carb to clean the valves, heads cylinders and piston tops.
It does a good job too because any time I tore down one of my motor's, it would not have any carbon build up in it.
I have torn them down even after 50,000 miles to find no build up of carbon.
Kurt