Close. Neodymium and some silicone rubber putty stuff (that may or may not contain an epoxy component, I don't know the chemistry behind Sugru.) But it's not a two-part product--you don't have to mix the “A” and the “B” compound to start it curing. It reacts with moisture in the air to begin curing, and remains rubbery once done.

EDIT: Epoxy putty is pretty cheap though, and what I'd probably use unless I needed it to be flexible.