Yes you can use water on a warm engine, when it reaches the combustion chambers it violenty turns to steam and breaks all of the carbon loose.
We used to do that on carburated cars, drive it for 10 min, remove the air filter cover and use a squirt gun and spray water into the carb.
The engine speed would slow, she would buck and rock and hate you but man she ran like new.
Worked everytime.

http://www.seafoamsales.com/how-to-u...treatment.html

http://video.google.com/videoplay?do...0865726229173#

 

no ****....i knew about water injection for the purpose of increasing horsepower... but didnt realize it had been used for cleaning... very nice. so how much water would you use like a whole one of those wal mart water squirt bottles from the hair products section ... you know the ones you buy loose i guess about 8 or 10 oz misted in? oooh or maybe the fuel system treatment in one of those bottles misted in? yes no ... thoughts?

 

I would use only a few ounces, it wont take much.
The problem is going to be regulating how much goes into the engine, to much and you risk serious engine damage.
A few ounces of water sucked in and then the cleaner in the gas tank and you should be good.
Then after your next oil change do another bottle of cleaner in the gas tank as good measure.
Then use only good gas and use the cleaner once a year.