It is very interesting indeed. I've only shared this info w a very small group of friends. Like 7 total. Yes in sewers, mainly vs trash heap bs thats the only place I like to farm. I've received nearly 20 pink drops from him. Now as you may know, I am more of a pvp ctf player, I dislike farming and pve.
Skeptical were my friends lol. At first. Then pow drop, instant believers. There were some fairly long runs without pinks like 8 but mainly 1 in five sometimes 25%..