No, what he's talking about is using SeaFoam poured down the brake booster line on the intake manifold to clean all the carbon and crap off you valves and pistons.

 

SeaFoam is an "all around" engine cleaner, you can put some in the gas tank (but I wonder how fast the stuff dilutes?)

But yes with the engine running (you may need someone to keep a little pressure on the gas peddle) disconnect the hose that runs from the master cylinder to the intake, on the master cylinder side, and use the suction to pull the liquid from the can, once done let the truck sit for about 10 minutes, start it up and watch the smoke.

Edit: dodge_dude beat me too it..

 

He's talking about pouring 1/3 of a can of Seafoam into the vacuum line that is attached to the brake booster. Do this while the truck is idling. the rpm will rise when you dis-attach the vacuum line from the brake booster. Pour the Seafoam into a bit at a time into the vacuum line careful not to choke out the engine. When you have put in 1/3 of a can, shut off the motor, wait 5 minutes, reconnect the vacuum line to the brake booster, start 'er up and wait for the smoke to clear. There could be a lot of smoke. I just did this yesterday. There wasn't a whole lot of white smoke out of my exhaust. I've seen videos on you tube of people seafoaming their engines where there is a lot of smoke. My engine light was on before this treatment. Not lit after the treatment.