You still want to do oil and vacuum intake too, but now I've seen the seafoam site seems to say if you use it in oil the first time, it should be as a pre-service cleaner and drive it 30-100 miles, then change the oil since it's going to be dirtier after this initial use.
Then after that it's just maintenance and oil change isn't always necessary after using it, just keep an eye on the oil color to make sure.
