Gorgeous,gold-silver decorated,carved blades were not used in battles.They were too expensive for that. Thats why many of them dont have nicks at all.They were just for show. Battle ones were very simple. If those ones are considered, most of them were used and had blood stains once or more in their lifetime for sure and were cleaned as soon as possible. It doesnt has to stain the blade. Once I wounded my hand quite deeply by a sword while cleaning it, and some blood stayed on the blade for almost 24 hours till I had oppurtunity to clean it. Now there is no sign of this battle

on it.