Thanks for the replies, they are all great and making me rethink the dehumidifier water option.
The reason I do this is my house water is full of minerals and leaves heavy waterspots when rinsing my brass.
What do you suggest for me to rinse my brass cost effectively?
Theoretical, as in *I* haven't done dehumidifier water:
Dehumidifier water is fine.
Dehumidifier water with a few drops of bleach is fine (which is correlary to treated municipal water), depending upon how much bleach YOU add. Plus, the longer you let your drops of bleach treated water set, the bleach dissociates more. However the water is sanitized at initial drops & mix. -Slightly more complicated, however for this use & volume is so.
Water spots, tarnish etc using straight tap water (municipal treated or well), is more likely than not "hardness" from minerals.
Folks overcome hardness by using a *little bit* of lemishine (citric acid). As in a 9mm cartridge case full or so (I do), however is dependent on water hardness, which can also change during the year in some municipalities.
I also add a touch of car wash/wax.
So for a tumble load, I do: few squeezes of Dawn, cartridge case of LemiShine, bit of car wash / wax (cap ful). For handgun ill do the car wash / wax with first short rinse water tumble, then another short rinse.
However, I also dry them all very well (commercial brass dryer, like a food dehydrator). Have done oven & hot sunny day/black towels. Brass dryer just is easiest for me...