No because it will temp them to go out and repeat other crime. How will the police be able to run name of suspect who may fit the profile of a crime committed in the area. If you do the crime you should live with the punishment.
You should not do that. Do to the fact the hair is very delicate after a perm. You putting on unneeded stress on your hair, which is going to cause your hair to began to break off and leave spit ends or lose of hair.
You should use foil because when using a cap the color can leak thru.It is also more precise and it helps with the speed of how long its take the color to set. Most hair dresser use foil.