I use dish soap and water to clean both the silicone and microfiber sides of mine. Lather it up fairly well with a sponge and rinse thoroughly. Then let air dry overnight. It does wonders for removing oil buildup that transfers over time from the screen to the MF, as well as other tiny pieces of debris that gets picked up by the MF. I wouldn't do that with a leather one though.
i've used a gentle soapy water hand wash (small dish and a cloth or sponge) numerous times before now, even on my grubby new ASK. doesn't harm the thing per se, but it is most delicate, so be gentle with it![]()