Move clips from one timeline to another

Hey there,
it took me till today to find out you can stack two timelines on top of each other. Really love this feature and I think it would drastically improve my workflow.
So now I have one timeline with all the usable bits of the source footage.
My goal would be to have my working timeline underneath and just drag the clips I want from the top timeline to the bottom one. That pretty much works fine so far, but the clip also stays in the top timeline. It would be nice if it would disappear there to indicate that that clip is used already.
I already tried holding ctrl, shift, alt and so on, while dragging it, but it didn't change anything.
The only thing that did work is pressing ctrl+x to cut it and then insert it in the bottom one, but that's not helping a lot, since I would always have to position the playhead at the right position to insert the clip at the right spot.
Does anybody know a way to easily achieve this? Maybe changing something in the settings? Or customize a special key?

I attached a picture of the timelines in which I want to move the clips around.

Dragging will make the copy. Cut/Paste may be your only option.