I said so, Bennieboj. So here goes ('cause somebody ERASED all the comments, so all my beautiful theories VANISHED):
1) Trade your Red Gyarados to R/B/Y
2) Do the Q trick, by hybridizing it with a Ditto (with Transform, obviously)
3) You'll get an unstable Transforming Gyarados
4) Hybridize it with a regular Gyarados
5) Now, you'll have a stable Shiny Gyarados with Transform
6) Trade it back to G/S/C
7) Do a link cable battle, your Gyarados against a Smeargle (with Sketch and Beat Up)

Get your Gyarados to Transform into it
9) Make Smeargle use Beat Up
10) Get your Gyarados to Sketch it
11) End the Battle...
12) Your Gyarados has now got Beat Up!
(By the way, this IS the 11/11 trick)
13) Do the Celebi Trick with it
14) Cheers to your shiny Mew!
(You can do this with any other attack in order to get ANY shiny Pok?mon!)
So, am I great or what?