I really can't believe the silly, unimportant things that some people get hung up on.
That said, running a B&B is a bit different. Recently we watched a couple putting duvets through an automatic washer - this was when we were buying petrol in France.
We don't use white towels, and we use the same ones - a set of 3, pale green John Lewis towels. We don't use a tumble dryer. Either they get a nice blow on the line if the weather is suitable, or they get dried on the little airer in the kitchen if not.
I remember that thing about frost being good for washing, from years back. I don't know the science of it though, but I used to be told it was good for terry nappies.