Absolute hygiene is crucial to avoid passing on any 'nasties'. Certainly toilet seats should always be closed before flushing because of spray . Maintaining a healthy immune system is essential to fight off the 'nasties'. But my English grandmother, my mother was Austrian so she may have had a different view, had a saying - you have to peck a picker or two. It was something like that and I can't find what it really was as it maybe a cockney saying but I think the point she was making was that we can overuse all different types of cleaning agents e.g anti-- bacterial sprays, wipes, disinfectants etc etc that do not allow our bodies to cope with some 'nasties'. Given Covid 19 we really need to pay greater attention to keeping ourselves and others protected , I fully understand that, it's a no brainer, but I guess the point I'm making is about our immune systems. Has our immune system got weaker because of all the other things we have used in the past. Just a thought. ☺