I have been wanting to make something like this for a while, a fully accessible silicone eye.
Here is a little summary of the materials I use most - how they are used and what to keep in mind when using them.
Quite often I find myself making small block moulds – simply building some walls around the piece I want to mould and then flooding the whole box with silicone. This procedure is extremely quick and most of the times suitable for reproducing a small number of items.
I finally found the link to the TV-ad for which I made the silicone frogs
A Friend of mine just conacted me on melting NSP and wax based clays - All regular plastilines can be liquidised, the problem is - they all remain kind of gooey