I've used mine straight from the box, but it wouldn't hurt to rinse them out first. You can either let them air dry or just
vape through the water remaining in the wicks. Gotvapes says the cup and wicks are "pre burned" to eliminate any chemicals or stuff that we used to have to burn off with a cigarette lighter, but there could be something on the coil; primer or something.
I'm using 70% VG with them and don't have any problem with wicking until they get very low. Then, I have to tilt them every couple hits or so.
The wicks are silica, so you didn't burn them. What you might have done is jammed the plug down into the coil and scorched the little lip on the underside of it. That would taste funny, but it won't last long. Or, the coil is sitting too high in that cup and contacting the little lip on the underside of the plug. I've had a couple do that but after a tankfull, whatever is getting scorched is no longer being scorched and it stops.
To fix it, pull the plug out using some kind of small tool. Don't pull on the nipple or you might tear it at its base. Look on the bottom side and you'll see a little lip that fits inside the rim of the cup when the plug is in place. You might see some tiny burnt areas. Use a small pair of manicure scissors or an Xacto knife to trim it. You don't have to eliminate it entirely, just cut it a little shorter. Check to see that the coil is not raised in the cup. Push it down if it is, so that it's sitting low in the cup. Without raising the coil, slightly lift the wicks so that they exit the cup near the top of the slits. This will improve wicking. Replace the plug carefully, making sure that the slits are lined up with the wicks. Make sure you get the plug straight. This is a bit difficult when the whole thing is assembled, so take your time and use some sort of little tool.
Normally, you don't want to remove and replace the plug unless you have removed the tube from the base first. When you re-assemble it after cleaning, put the plug back on the cup before you slide the tube on. That makes it a lot easier to properly fit the plug to the cup, since the tube isn't in the way.
Before you do all of that trimming and wick fluffing, go ahead and just tip it good and let it soak. You can turn them completely upside down without any flooding or leaking problem. Once they're really soaked, they wick very well. At least that's been my experience.