I enjoyed this D&D.
At level 132 combat I didn't find it too difficult or time consuming (10 minutes?).
I went in with melee gear and a load of rocktails. I forgot to bring in a summoned follower but didn't end up needing one anyway.
Tactics:-
1) Avoid going up path - you get pelted by Troll rangers and protection prayers seems to have little or no affect.
2) I concentrated on (when particular trolls were present) in order of engagement:-
a) Dynamite guy first
b) Mage Trolls
c) Summoning Trolls
c) Father Trolls
d) Range Trolls
e) Normal Trolls and "baby" Trolls (whatever they're called)
f) the diseased Troll and summoned beasties last.
3) Of most importance is to protect your special potion from dynamite Trolls.
4) Prayer: if Mage Trolls around, protect mage, then protect range until they're gone, then protect melee
5) Cliff:- Prayer Protect Melee until you see mage attack charge up, then Prayer Mage.
This got me through okay, even if a dynaite troll sneaked through in wave 18 and blew up my potion.
Spent reward on 64,750 prayer xp (at lvl 90 prayer).