Any shampoo that will help make wavy/curly hair straighter out of the shower?

1968Malibu

I'm a guy and don't care to use a straightener if I don't have to, hair is 2c I would say. Just want straighter hair out of the shower so I can put product in to hold that straighter look for a slick hairstyle.

Also the longer your hair gets does it become looser curls or tighter?

Thx