the forum search is a bit tricky so you can just google longhaircareforum MTG and you will get all threads on this forum that mention it. Its actually an oil that is used on horses although orginally was for human use but I guess they didnt take to the smell...which is not so but when mixed with other oils...gudluck
Basically, MTG stands for Mane, Tail, Groom. It's a sulphur based product sold by Shapley's whereas MN is an antifungal found in lots of different products.
Both have been used by members of the board(including moi) to enhance growth. MTG is very pungent so I could not continue using it, but switched to an alternative that is also sulphur based minus the rotten bacon smell.
I mix the sulphur product and the mn together. THe mn is very effective in controlling my previously flaky itchy scalp.
If you want/need more info, she's right-a search for either should provide you with hours and hours of reading pleasure
And, Shapley's recently created a human version of M-T-G that supposedly smells nicer and is just as effective called Sulu Max Gro: http://www.suluhair.com/ I don't know if anyone has purchased this new version yet and can speak to its efficacy, but you can search for this info. too.