A flinty cragbeast makes the best pet (imho). Let the group take it down to about 5% life - then claim your pet. Tash/Malo and charmed with True Name, related AAs – Charm lasts average of 05:00 during the trial for me. This thing throws out massive dps. Throw a scarecrow on it if you or a groupie "needs" to see what is going on - it is rather large :) Send in pet when tank has good agro or calls for assist if you play that way.
Also at a minimum, do yourself and your group (yes you all belong to the Chanter in your group!) a favor and have a dedicated ranger/druid in group who's first priority is snaring this bad boy EVERYTIME charm drops. It will regenerate its hit points and eventually will come for you. You will get a feel for when charm will break and keep communication with group open. The last thing you need is to have charm drop on a pull when the group is focused on the pull. Squishy Chanter = wipe in most cases.
Stop pulls - break Charm - re Tash/Malo/Snare/Charm - rinse/repeat as necessary, take a few more hit points from it here and there to keep it subdued when charm breaks.
I saw a post suggesting using a Pally to stun the pet to re-charm it. Great idea in theory, but bad if Pally is MA and charm drops in a pinch. You need someone looking out for your lack of AC first and added dps second - this pet will do most of the damage.
It’s not a continual 30 minute run for most of us out there. You need to be patient! Non-DC charming of a pet is high maintenance and some, if not all of your group, needs to share that responsibility for the benefit of the group and the run. Groups come and go - never the same peeps twice. EVERY TIME I've done it this way, we have won. Take care of the dps and you’re in there like underwear.
Heres to the SICKEST dps in your group! /cough from a Chanter no less. Did I mention haste? No? Even SICKER dps! Hope this makes your Tipt run a gimp event!