Even not dripping directly on to the goods, there's not a lot of stuff that you would be interested in getting out of a safe, but you will still be interested in even after being exposed to thermite. The list is basically "precious metals" and not much more, though that is admittedly a valid entry on the list.
In an analog to the somewhat frequent observation on HN that if you don't care whether the code is correct I can make it run arbitrarily quickly, if you don't care if the contents of the safe survive there's a lot of high-energy ways to blast it to smithereens. This is generally not considered a problem to be solved with a safe, though. If you want to prevent "being blasted to smithereens" that you'll need a completely different approach.
In an analog to the somewhat frequent observation on HN that if you don't care whether the code is correct I can make it run arbitrarily quickly, if you don't care if the contents of the safe survive there's a lot of high-energy ways to blast it to smithereens. This is generally not considered a problem to be solved with a safe, though. If you want to prevent "being blasted to smithereens" that you'll need a completely different approach.