How to report all card (names) in a deck, on emptying?

I feel like I’m missing something obvious, but I’m not sure how to do this.

I have a hidden movement phase, in which no reporting occurs. During this phase, a player may send various resources to hidden deck. When the phase ends, a hotkey command will send the whole deck to a discard deck, or a GKC will delete all pieces in the hidden deck, either is fine.

I need every piece in the hidden deck to be listed in a single report line when it is emptied. Optionally, identical pieces could be listed as “piece x 2”, but that isn’t important (and I want to avoid pointless “piece x 0” entries in the report).

How can I get this single line report working?

Nevermind, figured it out using deck expressions with dynamic properties and the like.