I donít think your problem has anything to do with the water, it sounds like, perhaps, an oily substance could have built up on this part of your hair and is resisting removal by the shampoo. Oil is usually removed well under normal washing conditions, silicone, however, which is found in many hair products can be more difficult to remove, particularly in products in which it is highly concentrated such as serums. I think a radical treatment my be called for. Before you wet your hair apply a large quantity of non-silicone shampoo (without Dimethicone on the ingredient list) to the hair in the area near the scalp where you feel it never gets dry. Gently work it into the hair and scalp, and then add warm water to allow a lather to form, rinse and lather again in the normal way. This process will remove any oil or silicone which has built up and you can start afresh. Finally, remember not to let conditioner touch your scalp. Conditioners are excellent for improving the condition of the hair but they can cause the hair to become too oily if they are applied to the scalp.