I get what your doing and thats neat. but if youre serious about looking for an alternative, you shouldnt use a paste that can expire or a paste that has water in it to evaporate. also the paste has to be room temp when testing. If you just got it out the fridge that will mess with the data, unless you do both fridge and room temp.
If you are just goofin around, then just do it up in whatever way.
Thats a tempror alternative, but I am testing for how long it will live. BTW I don't care about this video card.
Water boils at 100C, so I doubt my card will exceed 70C in its full load. Oil starts boiling at 190C Mayonnaise has oil, which will not evaporate or anything under 100C
And no, the video card testing is at room tempreture (About 20-25C) The case of the computer is closed.