It can work in a gen 7 double battle. Suppose you have A and B on a team against C and D, and A used some physical move last turn. This turn, A tries to use Counter, but B (or it could also be D, if the players are working together) uses Instruct on A. This forces A to use its move from last turn again, and hits C for some damage. C (who needs to be faster than A) then uses Counter to hit A, at which point A has also taken damage from a physical move this turn and can Counter right back at C, dealing an extra 4 times the damage of its original, instructed attack.