I do take the chain off once a year and soak it in a small bucket filled with WD-40 from morning to night and clean it all off till its nice and shiny again, I then dump it into another bucket of my Amsoil Dominator 2 stroke full synthetic oil that I also use to periodically lube it with during the next year. I do that overnight until the next morning, wipe off all the excess oil with microfiber cloth and just throw it back on...The synthetic oil gets into every little nook and cranny and keeps the chain nice and loose for me...I still have spare new chains to use if I ever need to but my old chain keeps passing inspection for me so I see no reason to replace it as of yet.
I did the same thing with my old Huffy frame bike as well with another chain I had on its Seeutec motor and had over 3,000 miles on that one with no real stretch that I could see and was still perfectly good to use as well.