As always, it depends. If you are at a NL table where all-ins are often called, a 3-bet may be kind of a joke. You could use it at a wild table to try to get the others to behave somewhat reasonably, keep the pots lower and the risk lower.
It is unlikely to have much impact at the micro level, where the betting patterns go quickly from 3xBB to all-in. That said, it might serve to rein in a LAG, make him consider not raising so often. It could also get him to shove and then you could be the one folding to pressure -- and, trust me, most people at the table will notice that. So use it sparingly, against someone who might fold -- and try it out the first few times with a big hand so you can call a shove if necessary.
On the other hand, it is a bit shocking at most limit tables.