Has anyone tried dye shampoo?

Hair dye shampoos are so popular... I'm thinking of buying one too...

I tried dyeing my gray hair for the first time a few days ago... but it felt a bit of a hassle.

I also became interested in dye-colored shampoos..

For those who have used it, does it actually dye the gray hair well?

I know I'll have to use it consistently, but I'm curious if the color changes after just one use.