Mike
There is a valve on the port side of the motor that you screw the nozzel into. Read the can as I think you give two 20 second squirts per cylinder after warm up. You squirt until the engines dies and then wait a few hours before restart. The airbox thing is news to me. The excessive smoke is normal, as mentioned above, just make sure you get it all out at low speed. I am not the expert here as my motor mech races the Johnson and was in the initial development of the 250hp 6 cylinder with OMC. He told me to use the ring free in my 2-stroke along with the 2+4 conditioner. Knock on wood, I have not had any motor failures with my last two OMC's
I think we need a expert motor mechanic to help us on this board