I believe that vanishing an object is simply putting the object in a new place. So I assume you could use accio or another spell to recover it.

But didn't they say in the Deathly Hallows that Vanished objects "go into non-being, which is to say, everything"?

And also do u think there might be a connection to the Vanishing Cabinet?

well, i can't remember every line in the harry potter books, so i may be incorrect, but my overall impression was that they are put somewhere else.

But the Vanishing Cabinet is also just simply bringing something from somewhere else, I believe, but don't guarantee accuracy.

Also, if you know the answer already, then why waste posts?

I just finished re-reading book 6. How I understand it is that the vanishing cabinets are sold in pairs and act as a doorway from one to the other. In the case of book 6, from Borgins and Burks shop to the Room of Requirement at Hogwarts.

I'm not sure about vanishing objects. Perhaps they just come into being and go out of being. But I think they must exist somewhere (and perhaps the person must have to possess them) because otherwise nothing could stop someone from conjuring up a Firebolt or something. So it might work like a fancy accio spell but without having objecrts zooming around.

And Avada Kedavra works on living things and those living things don't diappear when it's used, they just cease to live.

no they cant be recovered. BYE BYE BABY BROTHER!!!!