Monsterkitty, I'm sorry you had a bad Leo experience. Many of the vendors will honor the 3 month warranty. If not (and you purchased it less than 3 months ago), contact me and I will get the bad part to Boge and send a replacement.
You stated something about a "genuine leo 510's for 7.95"; What is a Leo 510?
As for cleaning most folks do what they seem comfortable doing. I like the alcohol-hot water rinse method. Others are trying baking soda and hot water, some just blow it out. The trick is blowing it out and drying it thoroughly, no matter what method you use. Any water inside the atomizer may diminish its use. However, proper drying, priming with ejuice and use will keep it running a long time.
One of the main reasons for atomizers dying is the fact that the polyfill inside the Leo cartridge will shrink with excessive heat. This reduces the wicking process, sometimes stops it. Without the proper wicking of ejuice, the atomizer can, and will, become over heated. This will eventually pop the atomizer.
The Fix: Keep a pair of tweezers handy and pluck up the poly fill every time you refill it. Just fluff it up until it is about level with the open end of the cartridge. Then refill with your ejuice. I do this to my cartridges until the poly fill inside becomes too shredded (2-3 days). Then I toss it and start another. I've yet to pop a Leo atomizer.
There are several threads about cleaning and battery/atomizer care here in the Leo subforum. Check them out.