My teenage daughter has really, really thick long hair and is miserable about it ( 1st world problems I know). What shampoo and conditioner is the best for taming this please ? ( High Street pls, not salon brands). She is driving us insane !! Just below shoulders a and he won't get it cut shorter . It's slightly layered but super thick. Lots of it . She doesn't want to straighten it every day either . Any advice ?