I find protouch increases hold but you have to uses a very small amount or it will mess up glues when you apply them. Also it make clean up harder. I recommend it for just the front hairline area to help stop lifting.

Scalp protector....I'm starting to think it's just a gimmick. I've never got extended hold from it or noticed any benefit. Some have reported it helps, others say it actually reduces hold time. It leads me to believs it's pretty innaffective. At least for me it did nothing .