Not tried Prisoner but you have to go in with a very strong team and if they can resist silver debuffs then all the better! I am using variations of:
Alex with Orbit
Charlotte with Vipers or Troopers
KP with Greed/Cosmic
Madam with Singularity or my Warrior LOL at near max awakening with Trooper talisman
Both are pretty quick and often finish with little to do damage and they never die. I think the LOL based one is fastest (1m 28 secs is quickest I have done) with an average of maybe 1min 45secs but Madam is not far behind and her fastest was 1 min 42 secs.