I've always washed my eggs in cold water, never had an issue with bacteria. In fact, I incubate cold washed refridgerated eggs all the time. I also eat cold washed eggs, never gotten sick. I don't use soaps, or brushes/sponges, just rub gently with my fingers.Someone may have been sheltering in the nests during the rain. Always good to have other roosts and places to 'be' during inclement weather...that is why we stress larger coops. Rainy days here almost always make for dirtier eggs due to muddyish feet.
Do not use cold water...
...see the posts above about water temp, and here's more:
Eggs should be washed in 'water warmer than the egg'.
Simple physics, using colder water will cause the egg contents to contract, causing any 'germs' on exterior surface of egg shell to be pulled into the interior of egg thru the shell pores. Using warmer water will do the opposite.
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