Passing objects

I am trying to develop something conceptually easy, butquite a challenge in SL: an animation where an avatar gives an object to another avatar.

For example, avatar A has a cup in his right hand. He raise the cup at shoulder level and pass it to avatar B. She raise her left hand, and catch the cup. The cup should pass smoothly from one avatar to the other. I suspect it can be done by attach/detach objects from and avatr to the other, or using the same attachments that become visible/invisible simulating the move, but in all the test the trick is quite "visible". I am looking for something more realistic.

Any hint appreciated.

Can the AVs be on poseballs?

Does it need to work with AVs of different sizes? (IE, arm lengths?)

Do you need the receiving AV to actually end up with a copy of the object?

Having them on poseballs would let it be much more precise than using a hugger type script where alignment only roughly matches...

Having an object inworld that's not attached lets the transition be flawless but the alignment at start and end wouldn't be as exact, having two attachments as you describe would make for only one but probably more obvious glitch, so I guess subjectively, which would you prefer?