I have a theory that your hair adapts over time to how frequently you wash it. Since I washed mine everyday, it produced more grease in a shorter time period. I have no idea if this is scientifically accurate or if I just reconciled myself to having slightly less clean hair, but after a couple months of washing my hair on average once every other day, it seems a lot less greasy the second day! Granted I can still tell a little bit of difference in appearance and in how it reacts when I style it, but I can actually stand to be seen in public with unwashed hair now, whereas before it felt like nails on a chalkboard.
So I'm here to encourage other girls like me who think they HAVE to wash their hair everyday to give it a try. Make sure you have a lot of hats to wear and lots of baby powder to rub into your roots on the second day of not washing for the first month or two, but there's a good chance that after a while your hair grease will calm down and you'll be able to save some time in your morning routine (and in your hair's well-being, since it dries your hair out and is just generally not going to improve its health by washing it every day)! Not to mention you'll save money on shampoo since you're using half as much. Which is a big deal for me and other girls who don't buy cheap shampoo and have to use a lot of conditioner because their hair is on the longer side.