I agree the best way is to never leave and go to the tower - who cares if you run out of room. The Blues and purples will be at postmaster. I've gotten about six exotics from roc strikes and each time this is how I did it - on weekends just grind strike after strike seems to be between 40- 50 strikes you should get an exotic. This seemed to work for me but if I went to the tower I noticed it went well over 50 strikes - good luck- it sucks and I no longer do it but I got more exotics than purple ball drops -- lol that's the truth

Calling B's here I have done so freaking many strikes always get crap

Iam due about 5 then (had two legendary)