I won't speak for all instructors in the state, but it's my policy that if you have a permit from a state that has the same basic requirements as SC (8 hr minimum, range time, etc.) then all I require is a short version on SC law. This can be done by coming in later in the class, so the entire day is not wasted. The key element here is that the old state requirements must be at least as stringent as SC.
Howard