I'm glad you are all getting results with this tactic. I tried it enough times with different teams to test whether or not it worked, but its nice to know others are having some success.
PS2 - With regards to opposition instructions, I only really set these if the opposing AML/AMR's are especially good. For example, if I am playing against C. Ronaldo I will force him onto his left. You can also do the same thing for superb forwards that are one sided. If they are "Left Only" then try to force them onto their right foot. Simple, but sometimes frezzes them out of games.
The other cheeky thing I do is to rile dirty players. If say I am playing against someone like Diouf I will set my players around him to tackle HARD. The amount of times I've had opposing players sent off is pretty amusing. Its sort of cheating, but it happens in real life.