You can rinse the clearomizer out with hot water. You probably should have done that first anyway. Clearomizers often contain some primer fluids or other oils left over from manufacturing.
If you are using the standard dual coil carto with the DCT tank, you can expect to get poor results. Your LT is cutting your voltage to 3.7. Stick with cartos or clearos as close to 2.5-3ohms as you can.
Clean your clearomizers. Use a cigarettte lighter to burn the wicks, being careful not to burn the shrink tubing or insulation on any wires. Burning the wicks will remove any leftover stuff from manufacturing. Just pass flame over it for 5-15 seconds. They won't really burn, but any smoke coming from them will be the stuff you dont want messing with your flavors. That will also help dry the water left over from cleaning. Flame them until there's no more steam or other vapor coming from them.
Then, reassemble the clearomizer except for the top plugs so that you can see your coil. Do a dry burn on the coil. Just pulse the power on and off for a few seconds at a time until it glows red immediately and you don't see any more vapor coming from the coil. 3-5 seconds on and 5-10 seconds off. Blowing on it between "on" cycles helps cool it.
Once the coil is clean looking, glows immediately and doesn't give off any vapor, fill it back up and vape.
If the coil was really crusty looking, it'll be coated with a greyish ash. You can rinse that off and do the dry burn again if it's really thick. Sometimes, instead of rinsing off the ash, I use a very fine paintbrush with stiff bristles and sweep the ash off the coils. If you do that, be sure any lost bristles are blown off when you blow the ash away.