[voidpointer]

If it's just about having a usable safe, it's an easy decision. They just need to decide whether the cost for the locksmith is worth it for them to have a usable safe...

If it's about what might be in there... shouldn't it be fairly easy to drill a small hole (given the right type of drill) and use a miniature/endoscopic camera to take a look?

[sneak]

High quality safes have glass drill plates that break when drilled and clamp the mechanism shut.

[unnouinceput]

So? You still have the hole and can peek inside to see if is empty or not. And if it's not then get it out and sledgehammer it in your garden, just for fun, then sell it to your local junk yard.

On the other hand, that you want to use it, then design your own robot and try all combinations. There is no time constraint since you're the owner, no need to "finish in 3 days"

[rusticpenn]

Whoops, I seemed to have misplaced my endoscopic camera. \s

[Ensorceled]

They are dirt cheap on Amazon, around $40 for an inspection camera.