If you use warm water and enzyme detergents, then it is easy to get out nasty things like blood.
I'd be very careful with that, even after several washes there's typically still enough traces present to get a DNA read on whose blood it was, and then the best alibi in the world won't help you.
Our F&P top loader's manual recommends doing a regular hot wash to help keep it clean, and we normally do warm washes anyway as if you are using a washing machine detergent that has enzymes (such as the Persil we use), the enzymes are useless in cold water and are a waste of money. If you use warm water and enzyme detergents, then it is easy to get out nasty things like blood.
Generally agree but Persil says blood comes out best in cold water.
That Persil web site is wrong then. Hot water will set blood, but warm water is not hot enough to do that, but is hot enough to make the enzymes do their job. I have got out lots of little blood spots over the years this way, and one really big bit too.