I have an engineering degree, and just enough medical background to be dangerous...
The problem with materials that aren't "medical grade," isn't just with the base material, it's with everything that comes with it. In other words, the silicone itself might be ok, but what did they use for plasticizers, release agents, packaging additives, etc...? Who knows? Even if you do get confirmation on the base material, it still doesn't mean it's safe to place the finished product internal to the human body...
My "problem" is that my background has made me over cautious. I guess that's the better result, but I've had enough infectious disease training, and manufacturing engineering background, to know that there are very few things I'm willing to put in my body...