I have a bit of an issue with my hair, in that it gets oily rather quickly. Like a day in after I've even changed sheets and washed, and it still gets oily by the next day. I've tried soaps from Stirling, VO5, and a few cheaper brands for shampoo. I'd still prefer to keep it somewhat cheap, but I'd settle for paying a bit more just so I can go two days without needing to shampoo again. What exactly might be a good shampoo for somewhat thick and oily hair?