I love this trick I learned back in high school. Sometimes all those products just build up in your hair. Every shampoo brand has their own deep clean shampoo, and they're usually not cheap and can be damaging. Here's what I mix, 1 travel bottle of baby shampoo mixed with half a tablespoon of baking soda. It will create so much lather and strips all those nasty products and oils away. It will leave your hair a bit dry if you don't condition, so remember to do that. Try it on Sunday after a weekend of hair torture.
Note: I'm a blonde and I can't say if it's color safe if you dye your hair darker.