It takes longer than 6 weeks to self clean.
go to
www.longhaircommunity.com and look up WO (water only) washing.
It takes around 6 months. The first two minths, it goes greasy, then it goes dry, then greasy again.
Being WO is marvelous if you can manage it. I have a friend who hasn't washed his hair for 6 years, and it is beautiful!! I also have another friend who hasn't washed his for 3 months and it is horrible...
I would recommend starting by cutting the amount of times a weekyou wash it, and ow you wash it.
For example, if you wash it every day with 2 shampoo washes and one condition, cut one of the shampoo washed. There is no reason for ou to be shampooing your hair twice!
Then, cut to every other day, then every 4th day etc etc.
When you have it down to washing weekly, then try not washing it.
If you suddenly stop when you're washing your hair every day, it can cause scalp problems because your scalp has to work at getting id of the excess skin and oil, whereas it didn't before.
While you're on Longhaircommunity, look us CO (conditioner only) washing. I do this during the winter and the height of summer when i feel that my scalp is most dry. Conditioner has enough active ingredients to effectively clean your hair. It doesn't give it that squeaky clean feel, but it does feel clean. It also doesn't strip the hair of its oil, and therefore it doesn't strip the scalp as much.
Good luck!