Its just a sheraider (sp??lol) valve...some have it some don't. Just remove the air box cover and run the motor for the last time while spraying the fogging oil into carb throats. Shut the engine off and your good. Does the same thing. The valve just makes it easier and quicker. Better to go through the carbs as you'll get in on both sides of the pistons, in the carb throats, and on the crank and reeds. If you put it in the spark plug holes it will just sit in the cylinders. Just my opinion...but I wouldn't spend the money on the little valve...just remove the cover and do it that way.
"But if serving the Lord seems undesirable to you, then choose for yourselves this day whom you will serve, whether the gods your ancestors served beyond the Euphrates, or the gods of the Amorites, in whose land you are living. But as for me and my household, we will serve the Lord.” Joshua 25:15