Is it okay for anyone to use a scalp scrub?

Recently, my hair has been getting oily and itchy frequently, so while looking into various things, I found out about scalp scrubs.

They say it removes dead skin cells and impurities, but honestly, I'm not sure if I need it yet.

I was confused whether it's only for oily scalps or if people with dry scalps should do it too.

Is it absolutely necessary to use a scalp scrub regularly? Or should it only be used in special cases?

For example, I'm wondering if this applies only to people who frequently use styling products or have severely clogged pores.

The product descriptions all look good, but I'm hesitating because I'm not sure if they actually suit my scalp condition. 

I want to know exactly if scalp scrubs are suitable for anyone to use or if they are recommended only for specific scalp types.

I also thought that only people with flaky skin should use it.