I recently saw someone on my server who had metas in every socket. I was curious on how he did it and I decided to figure it out myself.
First you need Cheat Engine.
Second buy a bunch of metas you want to socket.
Third look up the item number for the meta gems on wowhead or thottbot. (ex. Thundering skyfire diamond is 32410, the item number is the last numbers in the URL)
Fourth Search for the hex values for the metas your using, in this case 32410.
Fifth select all values on the left and add them to the bottom list.
Sixth select all then change their value to the item number for any other gem.
Seventh freeze all adresses and socket those puppies.
Its not crazy op, but it is fun to mess with.
Tested and working on Chaos Crusade.