17C , some rain

I am forbidden to use the shower at work. Legionellosis has been detected in the  showerhead, the boss told me I couldn’t ride in tomorrow because of it. There must be a way around this, maybe wash in a sink for just one day- it depends how long it takes to sterilise it. I have to wonder about the shower here at home- perhaps I should remove the head and leave it in a bucket of bleach overnight. It’s maybe worse here because I only shower at home once a week (the mostly shower at work). Is this why some people leave the showerhead lying on the shower floor to let the water drain?