Norovirus can survive being dried out and can live on surfaces for up to 2 weeks! E. coli can remain contagious through fecal matter for up to 9 days.That’s why you need to disinfect your plunger after cleaning it.
You should clean your plunger thoroughly every time it’s used. You can start off by flushing the toilet and using the running water to give the plunger a first rinse. Then, do a bleach soak as outlined above.