I prefer the easy way: idle the engine and squirt the cleaner in the throttle bypass until it stalls and let it sit for an hour. I know your way is better, but my way is easy enough to do every oil change or so.
Rally with your goggles on!
2000 Pitch Black ZTS Auto (230,000+ miles)
2007 CD Silver ZX4 SES 5spd
Zetec Crew #190