I want to have pin straight hair,

I've done keratin treatments the 3 months ones. but I want something more long lasting. My hair is damaged from bleach and dyed over, the keratin didn't even last but less than a month.

I've heard of a Japanese straightening treatment, or chemical straightening.

Just don't know the best option.

My hair right now is just a little frizzy and some waves here and there some straight pieces but so inconsistent. I personally like my hair really straight.

Any advice or thoughts? What to ask for at the salon?