Having several large pots of water (with lids) can help you keep up with the multiple-person demand. It isn't just the heating-up time, it takes quite a while to cool down so it's usable. Having a series of pots can remove much of the nuisance value of having to do it.

Be careful about washing mucus membranes with contaminated water. Even regular E. coli in the eyes can turn into a problem.

Sue