Dar para el pelo

Dar para el pelo
 

I think it means slam somebody, or to whoop, or shellac someone, but certain internet sources indicate that it may be a mild reproach. What do you think?

It gave anything for the hair.

A shampoo?

Poli, I verified a lot earlier today that this is a mild reproach - stop that or I'll give you what you deserve - but I think it could certainly come across as a harsher warning depending on the tone used. Your other translations seem to fit that category.

Agree with Rusty.
Only the context or the tone shows how hard the "I'll give you what you deserve" is
saludos :D