Hair Washing Help?

Apologies if this is in the wrong forum.

I have mid-back length, unlayered hair that is naturally frizzy, tightly curled and waved. It's almost perm-ish, but I HATE it. It shrinks up to my shoulders and looks terrible at the top, so I straighten it often.

The only problem is, is that it takes me a half hour to straighten the entire thing when dry, and a full hour when it's wet, so I've resorted to only washing my hair once a week. Disgusting and cringe-worthy, I know.

My scalp gets itchy on the fifth or so day, and it becomes greasy, but I don't know if I have the time or patience to wash it twice a week and go through the hour of hair-straightening Hell more than once a week.

What should I do?

Note: I do not have a blowdryer. I wash my hair, put it in a bun, and straighten it in the morning.

Hair washing a shampoo shield fits on a child's head like a cap, and helps prevent water running into her eyes. You can also use a thick layer of Vaseline on her forehead to help stop water getting in her eyes. Or let her wear swimming goggles; they keep the water out, and she can put her head under the water for rinsing and still open her eyes.