Careful about saying cloth and detergent without specifying what type of detergent and cloth. An abrasive cloth used with Comet cleanser would scratch Gorilla Glass 3 pretty badly.
I would recommend something that is safe for eyeglasses. That's what I use on my Lumia, my laptop, and my glasses/sunglasses. I use a microfiber cloth with a lens cleaning solution. My lens cleaning solution is 65% rubbing alcohol, 35% distilled water, and I add one drop of Dawn dish washing detergent (others will work fine as well) for each quart of solution I mix. A quart will generally last me about 3 or 4 years, and my wife uses it on her laptop, her glasses, her phone, and we also use it to clean our big screen HDTV, and my 22" HD computer monitor.
Cleaning solution is cheap as dirt if you make it yourself like that, and it's pretty much the same formula where you pay $5 for a 2 ounce bottle.