If it's NPC behaviour you're investigating then solo would be better. Any station with a single pad of a given size will do, outposts and megaships usually fit the bill.Interesting - I had read this before, and tried it with seemingly no success, so assumed it was just people drawing incorrect conclusions from observations.
I'll hold my hand up if I'm wrong - even though I tried it, it honestly sounded like the sort of thing FDev wouldn't implement in a million years! Any suggestions for a station that's likely to be busy enough to test it out?
Edit: I guess the megaship, but presumably only in open?
In my case it was Rackham's Peak which was both an outpost, very busy, and you were guaranteed to have an NPC spawn before you could get within 7.5km. That's not exactly an easy station to drop in on for a bit of testing. Unfortunately I can't think of any other outpost that's quite as busy off the top of my head, although in my experience any outpost will spawn an npc within a couple of minutes if a player doesn't take the slot.
I'd heard various versions before, like "request once for every pad and it will clear one" or "Target the docked NPC to make them leave". At first it didn't seem to work untill I added the 30 second wait, and then every single time the pad would immediately retract to turn them round. I'd position myself so I could see the pad behind the left panel.