Sanitizing fresh water tank

Thanks for all the responses guys. Since the beginning of May , I've gotten H2O from VA. to ME. in 5 states and forgot to drain the tank last time I came home, and while getting ready last week for a few more weeks on the road noticed an egg smell so there was definitely a need to sanitize. Never knew the hydrogen peroxide trick, thanks. My BIL runs a filter plant for 30K residents and always give's me stuff that he uses. (You need better stuff than clorox) lol, but he's out of the country so I needed you guys to remind me. I've always used clorox just wanted to be sure. Funny thing also with public water N.Westchester Joint Water Works (ours) had stopped using chlorine for a # of years, but has again started using it again, after a coalition of local Dentists, led by mine convinced them of the benefits. Maybe this post will "remind" others, thanks again. K Mac