Jon you really need to check with the manufacture and ask what they recommend. For instance enolmatic filters can be back flushed but the filters I use in mine cannot. Typically I flush mine out with warm clean water. Then I run a pail of oxy clean or PBW through it. When it is half empty, I shut it off and let it soak about 5-10 minutes. Then I run the rest of it through. Then I run another pail of fresh water through it to rinse it out. I store the filter in a capsule (pvc) with a meta/citric solution.
I own a .20 and have not used it yet. I use the .45 for everything, reds and whites. I'm not aware of wineries going to .20, but why not! I was going to use mine for my apple wine but didn't get it in time. Remember none of my filters are absolute at home.