I only bothered with an accountant when I ran a limited company.
The OP is self-employed so he doesn't have a company, but it's still OK for him to invoice himself to transfer personal property to business use, but then of course if he uses for himself he has to declare payment in kind, OR hire to himself OR keep quiet.
When you are self employed, you and your trading entity are basically one. You're a sole trader, but the liability etc. all remains the same. There's no real difference between company property, and personal property. It's when you go to being a limited company that you gain a seperate legal entity for the company. I'm not convinced that it's OK to do as you suggest above.