Here's what I found out with the flax seed hair gel idea:
It will go bad in just a few days. I tried putting it first in a sealed container with some tea tree oil, then in an open container with no added anything, still the same. It does also make the hair greasy.
The hold is ok, it's not like any store product and it's not supposed to be, all together I'll probably keep using it until I find a better "glue" for my hair. :)