I am so glad the gel worked out for you; it really is amazing! If you check around on this site you will find several threads where people list their recipes, some of which include ingredients intended as preservatives. There is one thread in particular where a woman tested various preservatives in the FSG to see which ones were the most effective. The preservatives ranged from things you can easily get at a health food store (essential oils, citric acid etc.) to commercial grade preservatives. HTH:-)
Hair (CG since 3/31/12)
Type: 3c/b; Density: M; Texture: M-C; Porosity: L-N

Products
Cleanser: SM Moisture Retention Shampoo or DevaCurl No Poo
Conditioners: DevaCurl One Condition or Heaven In Hair
Leave-In: DevaCurl B'Leave-in
Styler: Ouidad Climate Control Gel or DevaCurl Volumizing Foam
SOTC: MO
Refresher: DevaCurl Mr. Right

Journeying back to gray!!!:
Last Henna: 11/3/14