So, though they look pretty similar, cranes and herons aren’t that closely related. Herons are part of Ardeidae, with other stabby-faced predatory birds like egrets and bitterns. Cranes are all the way over in Gruidae (I guess… also stabby-faces, but different, okay), and the two families are not even that closely related. 

That being said, both herons and cranes can, in fact, reach their terrifying knife faces with their weirdo spindly feet!

As I mentioned before, when you think about it, they are technically “birds of prey” - i.e. they are predatory birds. They’re distinguished from the true raptors by not having murder talons to match their murder face. Their “talons” look like they belong on some kind of beautiful, delicate songbird instead of a leggy fish assassin. Not at all suitable for murder.

They can grab with their feet, and will use them for very impressive high-kicks, but their primary “tool” is their beak. Anything that requires manipulation, such as nest-building, hunting, picking something up - their first instinct will be to use their beak.  So I guess my final consensus would be that they could bring something up to their mouth, but they probably wouldn’t.