The photo thread doesn't say how much bleach was used, or how long the filtration was run - but it seems like if I'm willing to clean the filter, that might be the least wasteful method. As mentioned, I have a DE filter. My neighbor does his own pool work. I've been encouraging him to look at this site, so I have to show him those images. Its really impressive.

BTW, Costco advertises 6% Clorox @ $12.99 for a case of 6 96 oz. jugs.