I seafoamed my Corvette 2 months ago. I poured a couple ounces in my gas tank, a couple ounces in my crank case for about 300 miles.
Then I used the seafoam spray can which has a little plastic horseshoe tube about 7 inches long which slides infront of the throttle body blade and cracks the blade open about an 1/8th inch more. What I liked about this was it opened the blade just enough to hold my idle about 2000 RPMs so you dont need a second person.
I sprayed the full can into the manifold which did not cause the engine to stall, so I poured a couple more ounces into the vacuum line. The car still didnt stall out, but I felt I added ample detergent. I shut the car off for a 1/2 hour, removed the tube in front of the throttle body, plugged in the vacuum line and started it up. I made 4-5 wide open runs and called it a day after I changed the oil.