Ok, I rarely post here because I usually I am on another forum but my conscience won't let me sit idle while I see a lot of people are having troubles with their cartoz. That being said, I will chime in with some helpful tips which may help a few. For those of you who don't me from Nu-Vapor, I am not a mr. "know it all" but I have been vaping for over 4 years and have tried just about every invention out there.
I have the delrin 5mm and the SS 5ml liquinators and use only the smoktech brand dual coil mega lr cartoz. I have tried others like boge, bauway, ce2 etc but the smoktech's seem to be the best so I will stick to tips concerning only those.
The Smoktech's can last weeks if you know how to use it, the biggest cause of failure is user error or lack of maintenance. I have been using these for months and so far not a single carto has ever been DOA and has never "shorted" out. The PV I am using is a Precious-LV2 set at 4volts under load, the juice is 100% VG Boba's Bounty and Gorilla juice by Avejuice.com.
Starting with a new 1 or 2 slotted carto(I prefer 1 slot), install in the liquinator as usual, fill with your choice of liquid but do not install on your PV yet(reason for this is to prevent accidentally pressing the power button out of habit). After this is done, do some inhaling on the drip tip until you see your carto saturated up the the very top and take note that most of the liquid in your tank will be gone. This may take a few minutes and a lot of sucking because the carto does hold almost 2ml of liquid.
When this is done, install liquinator on your PV, remove drip tip and carefully slide your tank upward just enough so there is room to fill the tank with a hypodermic needle. Try not to tilt the tank and keep the carto straight, if you tilt it to the side, more than likely it will leak juice from the bottom. Fill the liquinator 75% full or as much as you can without going over the top of the carto. When this is done, inhale and make sure that you can hear and feel a little gurgling. If you feel absolutely no resistance or gurgling, take a few more inhales without powering on your PV until it is felt.
After you absolutely sure that your brand carto is slightly over saturated, take a steady but slow drag with the power button depressed. The reason for this is, the very first inhale can determine if you are going to get that dreaded "burnt" carto taste or not. Many times I have accidentally pressed my power with my brand new carto not fully saturated and had to start off with that disgusting burnt taste.
Now that you should of started off with a fully saturated carto, the trick now is to make sure it stays this way. This is where paying attention can make for a carto that can last weeks, so every 10 drags or so, do some visual inspections and confirm that adequate liquid can be seen from the top. If not, all that you need to do is to do some inhales without pressing the power until that slight gurgle is felt and liquid can be seen from the top. Easy to do if you just remember!!!!!!
Note: if carto is flooded, remove liquinator from PV, tilt upside down to make sure that slot is not submerged in liquid and blow excess into a paper towel.
I also see that people are having problems with cartoz being blocked. The dual coil cartoz have a 2 piece flexible "cloth" like ceramic/fiberglass tube in the center which can get misaligned at times and "dry" burning can create a burnt thick black liquid in the tube. Make sure that you can see light at the other end, if not then some practice with a straight paper clip will be needed but do not try this unless absolutely necessary. If you have to do it, insert the paper clip from the bottom and spin carto in the process. Do not force the paper clip or you will separate the 2 tubes and the carto will be history. Wipe the paper clip on a paper towel to check if your liquid is burnt, if it is, either you are taking drags that are too long, your voltage is set too high or your carto is not being sufficiently saturated.
You can also clean your cartoz up to a point, for those of you who want to save a few bucks, Smoktek.com does stock a cleaning kit which allows you to reuse your cartoz. Kit costs $6.95 which can pay for itself within the first 3 cartoz you clean.
Carto/Atty Cleaner Kit - Control Syringe, Luer-lock,10ml - Cartomizer Cleaner / Filler w/cleaning tube
Note: :I have nothing to do with this ECF supplier but from what I have read, the owner runs a pretty straight forward company. I am just trying to help people save a few bucks. Also, I use water to clean the carto instead of Vodka since I don't drink.

Seems to work just as well, just be sure to dry them out thoroughly before use.
Hope this can help some people, I hate to see unnecessary suffering by some while others are enjoying their liquinator virtually trouble free.
Aloha, Keith