Captured PCs

I tend to agree with dmgenisisect. When your PCs actually get captured completely by their own decisions, then the natural thing would be to have all of their things taken away. Sometimes its hard as a DM to make your players actually follow the true consequences of their actions, but sometimes it has to be done.
Having said that I really like dmgenisisect's idea about having the higher priority items going away from the "vault" first. Such as the staff you mentioned. Like he said, this gives your players not only a window to get their things back, but a motive to get out and get them quickly. To show them this time slot in character , you could have a Drow guard come up and brag about how their staff now lays in the hands of such and such and soon all their stuff will be gone, blah blah blah.

I am the Kind of DM that has my players pay completely natural consequences, but then again my players KNOW this about me. This all really depends on the feel of your group. If you want it to be something super easy, do the old west style "your stuff is all gathered in a bag across the room by a guard"
Or make it super super complicated. Just have fun with it.

Also, it never hurts to have the players to a quick slight of hand role before the game starts to see if any of them were able to hide anything before going down in the fight. Maybe a small blade? A lockpick perhaps?