Ok. first, the search link is up above. Pretty easy...click Search, and fill in the items you wish to find, in this case put in Evap ...
But this is about the best thread on it here: viewtopic.php?t=12911&highlight=evap
Although it's about mechanisms, that thread gets into a fairly detailed discussion about how & why evaps work or don't along with things that have been tried.
At this point I've tried it all and I too have given up and just punted, hauling mine out. I simply bought 4 7 gallon plastic "jerry" cans from Pep Boys and spray painted them so no mistaking that they are gray water. Very easy to do, easy to empty when done on playa, etc.
Such a relief not to have to deal with a messy evap pond at the end of the week. Just a disgusting, dirty job to deal with.....trust me.
The fox provides for himself, but God provides for the lion - W. Blake (attribution corrected)