Wouldn't the water need to be scalding hot in order to kill germs? I wash with cold water.

it's iffy. the soap is the important. water doesn't need to be quite hot to kill things. i don't wash with cold water, but that's cause i hate cold water. lol.

though, i can't seeing it being overly difficult to run some hot water into that.

Nah, it wouldn't be hard. I've heard of hot water being mixed with cold on toilets that sweat too much. They run some warm water to the toilet to stop it from getting so cold. The downside of course is increased hot water useage.

It wouldn't have to be scalding hot, just hottish. Of course if you tried to run hot water to it you would have the same problem as getting hot water at the sink it takes a few seconds for the hot water to work its way through the pipes and out of the tap, and by that time I'm sure the toilet tank would be full.

That being said, I'm contemplating getting one for my basement bathroom when we finish that.