Very cool. I am also looking forward to your tutorial.
There is someone on Etsy - Rita's Creations - that sells a pattern for this. I know I have seen it before though somewhere. I might be remembering something I saw on Craftster or something.
They are really sharp. I think I will be needing to make some as well. I bet my mother in law would low this. I do wonder how well they would be in the microwave - do you think it would have the same baked potato bag situation with a possible fire situation?