Beware that vaseline hardens and seems to expand when Really Cold, and will cause bad connections. When I say cold I do mean cold though, like <-100°C. Shouldn't be a problem for DIce or RAM/PCIe slots.
I strongly recommend against putting it in CPU sockets though, especially AMD sockets.
That silicon spray is amazing stuff for protecting boards. It's staggeringly toxic though and will cause severe alergic reactions in your throat as well as chemical pneumonia.
Spray it outside and use a good mask.
Once it's dry it's perfectly safe (wouldn't eat it, though) and wonderful.