I suppose after a good bleach cleaning. It was more a public appearance issue than a genuine sanitation issue. What do people normally put into washing machines — sparkling clean clothes?
Mine almost always have skid marks somewhere in them.
Is why God invented bleach. ;)
Seriously, it is more appearance than sanitation. Over 160F, not many diseases can survive. Modern equipment and soaps break down any fecal matter and it goes away.
/johnny
Not poopy-pants for sure.