I've done the water down the carby trick...but I usually let it trickle in.....carefully
and don't tell me it's dangerous, I know.. I've seen a car bend a rod while going through a creek.
What I reckon works well is diesel in the carby...lots and lots of white smoke ..... but I swear the car drives
noticeably better after the treatment.
Many years ago I seen a head just taken off an EH after this treatment and it was incredibly clean. I've been tempted
to give kero a go too.