Unfortunately, when you have oily hair, you have to use a salon professional product.
Redken has a shampoo on the market for oily hair called OIL DETOX (R260). It has microscopic lipo sponges that absorb the excess oil while on your hair, so that when you rinse it, alot of the excess oil comes out. You must shampoo your hair twice with this product. With both shampoos, when it starts to lather, you actually leave it in for 2-3 minutes to do the work for you. This gives the lipo sponges some time to actively aborb the excess oil. No hand work required.
Another mistake that people make when they have oily hair, is that they scrub the scalp excessively as subconsciously the hair feels dirty. The problem with ANY sort of rubbing / massage on the scalp is that it stimulates your already very active sebaceous glands.
When using a conditioner on oily hair, it is very important to only apply it to your ends. Do not get it near the scalp.
Alot of the time, especially if you are using shampoo from off the shelf, the PH is not ph3.5- ph5.5 which is what the hair and skin needs. Most of the shop products are a PH of ph7 and above. This will always give the scalp excessive dryness or oiliness.
You can sort your oily problem out. It will just take some lifestyle changes, and ofcourse a professional Shampoo.
Happy washing !