The peppermint oil, vanilla extract, or any of the other combos didn't really get rid of the MTG smell for me. I accidentally discovered a product called Vita-Fresh by Next Image while browsing in a BSS. I'm using the Avocado & Shea Butter right now to cut the MTG odor, and I also bought the Coco-Mango formula. This product is an odor neutralizer for the hair, that really works. Since it contains a significant amount of water, I don't think it'd work out for those who wear their hair straightened, but I wear braidouts and buns most of the time so it works for me. It smells nice and fresh and truly gets rid of the MTG smell. An 8 oz bottle set me back around $6. Here are the ingredients:
purified water, propylene glycol, isopropyl myristate, dimethicone copolyol, natural herbal extracts (sage, chamomile, burdock and parsley), avocado oil, shea butter, panthenol, vitamin e acetate, benzophenone-3, magnesium sulfate, tetrasodium EDTA, DMDM hydantoin, citric acid, fragrance D&C yellow #11, D&C green #6 (for the coco-mango formula, avocado oil and shea butter are replaced by coconut oil and mango butter)
I found a website for the company that makes the product:
http://thenextimage.com/new_product.htm