Nevertheless, it's a common expression. I often say I am going to take a shave. So do lots of other British people. I'm going to get shaved. I'm going to have a shave. I use all these. I don't remember ever talking about shaving myself. Whether it's grammatically correct or not, it's how a lot of English people speak.
Sorry everyone. I was trying to ask why it was neccessary for one to clarify that one shaves oneself every morning. If one shaved ones dog every morning, I could understand why that would need to be stated. If I said to someone "I shave every morning", they would immediately understand.