I always pre-hose down my really dirty cycling clothes but the reason for this is to keep the machine running longer without having to change the filters etc.
This sort of thing will happen a lot – my wife did it with our little one. Everything becomes a potential danger to him. My favourite was that my electic items were dangerous and had to be removed, hers were ok because the electricity was more powerful with mine. Cycle stuff in the same washing machine was another. Any item which had touched meat, even though it had been washed, was not allowed anywhere near the work surfaces, chopping boards etc. Any drink I left was too near the edge and I was causing danger to him. Going out of the house with him when there is frost on the grass. The list is endless…. Life became a constant fight, but there you go. She is a fantastic Mum and had his interests at heart, but I think there is a danger with mothers to just lose a slight grip on reality sometimes. Thankfully this period has more or less passed.
Anyway, what I’m saying is either put your foot down and fight it, or suck up the pain and do as she suggests.