http://www.jsm.jsexmed.org/article/S1743-6095(15)31919-6/fulltext
At the very least, ask them for proof if they have used it on themselves.
The news articles mention some unnamed 'self circumcision devices', I really don't know what qualifies as such. Some of them are probably cheap plastic crap that one should avoid like the plague.
While there have been stories about people successfully using e.g. a ZSR Stapler on themselves it is still not recommended to do so.
If anything goes wrong one is away from a hospital or medical help. A serious bleeding or infection resulting from an ill fated attempt at self-circumcision can result in hospitalization, loss of a penis or death.
Foolproof devices can be deceptive. You don't really know how to perform a circumcision -- hopefully the engineers who designed the device did, but you don't. If the design is flawed, or the device malfunctions you don't really know how to bail out of the situation.
PLEASE DO NOT TRY THIS AT HOME!
