I have read a couple of posts recently about folks having issues with their tempertaure probles by cleaning them with water. I can relate because I trashed a couple of them before reading in here that water is a bad idea. I have found an excellent way to clean them and thought I'd share since it's apparently a trend. I use the lens cleaning wipes that are designed for eyeglasses. They come in single "moist towelette" foil packages and are treated with denatured alcohol. They easily clean and sterilize the probes but leave no residue at all when dry. They're readily available at any grocery store, pharmacy, WalMart, etc...and are super cheap. A box of a hundred costs about $3 and will last a LONG time. I keep a box of them in the kitchen drawer along with my BBQ tools so they're always on hand.
As with pretty much everything else, there are probably a thousand different ideas folks will have that work for them but this is an easy, cost-effective way that I have found to be safe, sanitary, and not destroy a very important piece of equipment.
Just my .02 and getting change back,