When I got the Fujik stuff, I though, "Hey, this is what they use on all those DX lights!", LOL. In my experience, the Fujik does get hard, just not rock hard. It has a little rubberiness or spring left in it. If you have a thin shaving of it which is dried, it is still pliable and flexible.
cessnapilot, if yours at least 'solid' at this point, or is it still gooey? It should be at least solid, or solid-y. Are you sure they didn't send you the--wait--just looked at your link you provided.
Dude, you ordered the non-solidifying stuff. Just normal magnesium oxide grease, for stuff like CPU's. :( :(
I think you were intending to buy the "Thermal Glue":
http://www.dealextreme.com/p/fujik-silicone-thermal-glue-50ml-grease-like-4579
for much more money ($7.19 vs $2.14).
That stuff does solidify. It's like a thicker version of magnesium oxide grease, in some kind of adhesive base. I'm actually finding it quite useful. It's not hard like epoxy, and can be removed if you really want to. Has some 'give' to it. Feels like there's some kind of rubber compound in there, perhaps. I've experimented with thermal potting, filling in gaps, and even squirting it inside to fill up pills (one-way trip, probably). If it's a smooth surface and I may want to remove it, I try putting a thin coating of petroleum jelly or oil on first, but of course it won't adhese as well. But thinking about doing this between a drop-in and host. Would be removable if done right.
I've ordered some of the regular 'thermal compound' (thermal grease) you got, but it hasn't arrived yet. I assume it's just like any packet of white lifeguard nose grease which comes with CPU's, just really cheap in a little tub.