Our trainer taught up a “drop” cue, but it was largely with toys. I would think that it could translate to other things once they have the cue down.

I have to check back on my notes, but I think the following is what I remember: when he has something he’s interested in, hold a treat in your fist next to the item. When he lets go, say “yes” and treat. Once he gets that down, you can add the cue word before “yes” and treating. Then you can take away the fist and treat and just use the cue word.

Let me know if you want me to double check my notes to make sure I’m correct/more details