Without color; lacking characteristics which give variety. blank (Adjective). Free from writing, printing, or marks; having an empty space to be filled in; as, blank paper; a blank check; a blank ballot. blank (Adjective). Without expression.
Yes they do damage hair. Every time I have tried one ,I wound up looking like a Q-tip or my head looked like cotton. A perm will damage even more and look worse if you have been coloring your hair. There's chance of it looking okay if you don't color your hair.
I rinsed my hair in the shower and applied this leave-in conditioner that my stylist recommended at least three times in between my perm and my shampoo. So, yes, you can get your hair wet in the first 24 hours and it won't ruin the perm, but I would advise against using conditioner.