Here's the method I used to grind to GM during last year's halloween events.
(in great detail in case anyone else needs it)
Get a boat. Park it next to heart island.
Next, mark 3 runes on heart island, one for each tile of the island. (I used 3 because I tried gating directly to the island from the pit on my 2nd trip to get fighters, odds are 2 of those runes will be blocked by fighers 1 and 2)
Go to Jhelom, mark a rune for the fighter pits.
Hire 2 fighters, gate to heart island and have them follow you.
On the island release/fire them.
Back to Jhelom pits, hire 2 more. Either gate to one of your 3 runes on the island or recall to your boat, use the plank to get on the island, and gate into the Jhelom pits. Bring your 2 new fighters to the island and fire them. Repeat this step until you have at least 6 fighers on the island, just remember, after you have 4 on the island, all your runes will be blocked. You'll have to recall to your boat and gate to the pit to from the island to get the last 2.
Now to set up a macro. I used UOA because it was easiest.
Use Ctrl+Shift to bring up the names, drag each one's health bar off and to the side of your screen.
Record a maco, beg figher #1
wait a few seconds and go down the line until you've begged all 6 of them.
Stop recording, enter at least 10 second pauses between each target. This will give you a 60 second macro. (I did 11 seconds just to be safe) By the time you have finished the macro you will be able to beg from the first fighter again. (you have to wait a minimum of 60 seconds between attempts on the same NPC in order to get anything) You should have a macro that looks something like this. (obviously the wording isnt exact)
Use begging
Target #1
Pause 10 seconds
Use begging
Target #2
Pause 10 seconds
Use begging
Target #3
Pause 10 seconds
Use begging
Target #4
Pause 10 seconds
Use begging
Target #5
Pause 10 seconds
Use begging
Target #6
Pause 10 seconds
Speak (lets you know the macro has finished)
Once you're set up just stand there on the island and keep playing the macro until your eyes bleed. I would recommend leaving the boat there because you're going to need it again when you reload the island for your next training session. Be forewarned. Its boring as hell. Download a podcast or something to listen to while you're working. It helps a little.
