I've got two AR cheat discs - the regular one and a special Wind Waker one. I tried both and neither worked, got the same advice to read the Wii manual as you.
Looks like AR discs can't be used with the Wii then.
EDIT / Just found the following info on Codejunkies site:
If you have one of the later versions of Action Replay or FreeLoader for GameCube, you can use it on your Nintendo Wii when playing GameCube games. It wonÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢t work with Wii titles ÃƒÂ¢Ã¢â€šÂ¬Ã¢â‚¬Å“ itÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s a GameCube product after all ÃƒÂ¢Ã¢â€šÂ¬Ã¢â‚¬Å“ but those who trade in their Cubes and invest in a Wii can carry on playing their imported GameCube games with FreeLoader and enhancing the experience with Action Replay.
Owning an AR disc doesn't necessarily make anyone a cheater. It can increase the replayability factor for games and be very useful to help you out of a tricky spot that you just can't get past. Sometimes it can unlock things that you wouldn't ordinarily be able to do as well.
At the end of the day, it's up to the individual player how they play their game. If they find having a little help eases frustration and makes a game more enjoyable, then that's their prerogative.
Now, online cheaters I don't like so much. That's giving yourself an unfair advantage over other players. Behave like me instead - hide in a corner and snipe everyone! :girl_blum:
The AR is said to not currently work for the Wii, there are ARs in the process of being made, or may have come out already, but they come in the form of SD cards...or so I've heard. I do know that there isn't an official AR for the Wii yet.