Kerry hot water wont roll or bend the edge but it can reduce the sharpness of the edge,i'm not sure exactly what happens but if the water is too hot to hold your hand in it will begin to effect the edge about 90 degrees c,most household taps aren't really hot enough but commercial ones are and it just takes some of the keenness the longer in it the blunter they are but i've never seen any big change to edge geometry,leave the blade in there for a good length of time it can break when you bring it out specially at higher temps,most people don't believe it until it happens to them and some will be adamant the hot water didn't do although they did themselves,as for wiping i have a hand towel over the edge of the sink full of water and wipe the gunk off then dip my blade in water then do another stroke,there's no danger of hitting anything and i save water too