At some point a friend of mine had purchased a self cicumcision device. He said it took only a little digging on the internet until he found a site that sold devices. He used it and achived hisgoal of a tight tight circumcision. Maybe if something like this exists it would be the safest option

Google "Shang Ring". It's a device that is gaining popularity in third world countries lately as a quick safe circumcision. I learned of it from the Manmods site. Saw a video of a guy using it. You can order one on eBay for around $35.00. He used the no flip method, lots of good videos of it being used on YouTube.

I would say if your set on diy, this looks like one of the safer options.