A couple of tips that I have tried on the 510's that have worked.
I use my atty about 2 weeks then the draw gets hard (as a previous poster said) so I take all the old atty's (like 5 or 6 at a time-saved for this purpose) and soak them for a few days in crest pro health (blue stuff). Then I soak them for a few more days in water to get rid of the crest. I twirl them in a cup a few times a day for both steps. Then I set them out, cart side down for about a week and don't touch them. After about a week or so (maybe longer if you live in a humid area) I reprime it with fluid that doesn't have a good taste any more or I use straight vg. (it's gonna go to waste so don't use your good stuff) I burn it directly on the bridge a few times to get the remaining mouthwash off (just in case) then the atty is just about as good as new. (not exactly, but I would say pretty close)
The other tips I have tried are the blue foam mod and the plug. The blue foam is not good. Simply put, no amount of rinsing and rinsing gets rid of that scent. If you can somehow come up with a way of rinsing away that stuff... then it does hold the liquid perfectly.
The plug took a little bit of work and patience, but it worked fabulously. I used one of those silicon cupcake thingies (cut one up) and was able to get the perfect plug. You can actually put the silicon on a piece of wood, take an old broken atty and put it cart side down and pound it into the silicon. You get the perfect fit that way.
I also order the disposable e-cigs. I actually like the batteries and so far the atty's have been good for a month or two each (before being cleaned)
Hope this helps
