My unit has blunt needles, but is not allowed to use them until they get ethical approval. I was trying to find another unit within the UK that has applied for ethical approval otherwise it will take my unit about six months to apply and be granted permission.
The UK seems to frown upon the idea of using the buttonhole even though the practice has been around for some time.
A guy in my unit (Canadian HD) didn't want to wait like I did so he just started cannulating himself and establishing his own buttonholes (I just talked to him this past Friday and he told me). So I know it is possible just to do it yourself. The unit might want you to sign some sort of form to release them from responsibility though.