Are dead rags more of a mil/battlesim/ usa thing? I have never been to a site that has mentioned them, it has always been explicit hand up and/or deadman walking - it was quiet clear in the briefing that if you didnt have hand up/ were calling or hand hands on weapons in any form of 'ready' and you got shot it was your own fault.
They encouraged not mag dumping on players that might be dead, double tap is fine.
As @Tommikka mentioned, if you can be sneaky, do that. Any use of dead player markers is cheating.