In case anyone is confused about why you'd want to heal farm...
This setup is for getting the 'Damage Taken' badges.
Tough - 100,000 points of damage
Indestructible - 500,000 points of damage
Adamant - 1,000,000 points of damage
Unbreakable - 10,000,000 points of damage
Nigh Indestructible - 100,000,000 points of damage
Invulnerable - 500,000,000 points of damage
Immortal - 1,000,000,000 points of damage
Actually this setup is used for getting the healing badges, especially for the SG healing badges. When I ran healing farm at level 30 in about a weeks time I got 4 Healing Badges and 4 Damage Taken Badges. With the 5th Healing Badge at 1/2 way to completion.
There are far faster ways to get the damage taken badges than just standing in a pain crystal. Although if you could somehow get pushed into a pain crystal while resting, then that would certain be a fast way to do the damage taken badges.
The first step in being sane is to admit that you are insane.
I do believe you can use your pets GoTo command to push you into the AoE of the pain crystal while you rest.
you dont tick any faster on a red xtal when resting. It does work on fire though
Leader/Founder of Order Sixty-Six Guardian Server
You do realize that as a guide you left out both the "how" and "why".
I understand the concept and the considerations you pointed out but you should really add two more sections to your "guide" explaining exactly how to do it and possible motivations for doing it. Including the details of the healing and damage taken badges would be a classy touch as well.
I look forward to your One Man Healing Farm VER 2.0 guide. 
Centinull
How
In a CoT Temple mission, find a red crystal and evaluate its usefulness based upon the level of the minions and terrain around it. Then eliminate the annoying enemies first (earth thorn casters, nerva spectral daemon lords, succubuses, hellfrosts, etc.) located at crystal. Leave one or two enemies that are only damage dealers. Set henchmen to passive. Target one of remaining enemies and make twilight grasp your auto-attack. By control+left-click on twilight grasp. Head into red crystal's range and have henchmen goto your location or summon henchmen to your location and set them on passive. Sometimes enemy likes to run away from red crystal, but most enemies usually stay nearby. Fire Thorn Casters like to stay in one spot and attack with their long range attack. Wait for a few days for healing badges and damage taken badges to come in.
Why
There are only two reasons why anyone would be willing to do a healing farm. The reason for the one-man healing farm is that not everyone wants to spend a few days to help you work on healing farms.
1) You are a badge freak and want to get as many badges as possible.
2) You belong to a SG that has few healers. In order to gain the first two SG healing badges, one person can get them in about a week's time or less depending on their level.
Personally, I did it for the second reason and so I wouldn't play any CoV during exam week.
Damage Badges:
1st: 100k
2nd: 500k
3rd: 1 mill
4th: 10 mill
5th: 100 mill
6th: 500 mill
7th: 1 bill
Healing Badges:
1st: 250k
2nd: 500k
3rd: 1 mill
4th: 10 mill
5th: 50 mill
6th: 1 bill
Using healing farm I obtained first 4 Damage Badges and first 5 Healing Badges. Any more that is considered insane, even by my standards. 
The first step in being sane is to admit that you are insane.
/dark MMs are the best AT for the one man healing farm. However, in order for the healing farm to be effective there are a few considerations to make note of. This healing farm takes place in the CoT temples that most people hate using the CoT pain crystals (red crystals). The heal being used is twilight grasp and require all your henchmen out and passive and within range of the twilight grasp.
1. Level of mission: The level of the mission determines the levels of the enemy spawns and the enemy spawns determine the level of the pain crystal. Pain crystals give a different DoT based upon the level. A +1 pain crystal will produce a higher DoT compared to a even con pain crystal. Since you need a target to use, you don't want one that will kill you in two hits. Generally a +2 mission works fine.
2. Obstacles: Is the area of the pain crystal free of cliffs and obstacles? A flat room with little to no obstacles are considered the best.
3: Enemy: Does the enemy run away from your sight or use debuffing attacks? The best enemies are ranged attackers that never move from one spot. Behemoths, Fire Thorn Casters, and Guides work well with this setup. Nerva Spectral Daemons and Earth Thorn Casters are very dangerous for a farm.
4. Other Powers: Darkest Night and Tactics are the only useful abilities for a healing farm. However if you have another MM with a perma immobilize or perma hold ability that would work well too. I prefer Tactics over Darkest Night because I prefer being able to hit more often. However, if you have Stamina run both.
The first step in being sane is to admit that you are insane.