Need ideas on making insertable molds

I enjoy the feeling of inserting solid turd shaped objects, and am struggling to find the ideal material to use as a mold. I have tried using hard boiled eggs, but I am trying to make a bigger more 'turd' shaped object, with a rubbery consistency.

The closest I've come is using cornstarch mixed with water and a splash of olive oil, then microwaved gently until I have a gummy paste consistency, which I can mold into a log shape, and leave to set for several hours. The only problem is that these molds are still too delicate and therefore difficult to insert. They break apart and crumble easily, I need to make it more flexible.

Any ideas on what to add to this mixture or any other recipes you know of?

I don't like the idea of using gelatin due to how it's made and it smells like pig skin!

What about using the stuff that dentists use when making an impression. 'Dental moulding impression material alginate'. Hope this helps.

Alignate would work quite well or for more permanent toys silicone rubber is great. I have often thought about mixing some alignate and filling my bottom with it to see what shape it comes out like when set, (about five minutes). If you need any help with this material let me know.

Totally agree with Marcia. I'd offer my experience as well, but I'm a noob comparatively.

You can get silicone fairly easily, Michaels sells it, heck even walmart sells it in the craft section sometimes. You can also get it off amazon.

http://www.amazon.com/Environmental-Technology-1-Pound-Easymold-Silicone/dp/B003CHMZYM/

JMak