I use tap water, we live in a soft water area. My sister does too, but when I could visit her, her water always smells of chlorine so I wouldn't use that. Never had DOS, I've been soaping for about 12 years. I guess it's the luck of the draw. You've got some really good advice on posts further...
At work, as a teacher, if anything comes from home we have to quarantine for 72 hours. Same with my daughter who works in a clothes shop, any returned clothes have to sit by for 72 hours. I hopes this helps with time frames for setting things aside.
I just use tap water, but I love in a soft water area and I've had no problems, if that helps. I usually run the child two until it's cold so there's no hot left in the tap.
We're Star Wars fans in our house and it's a family joke, my husband kept getting Kylo Ren's name wrong. The joke is he is the Scottish sith - we come from Scotland.