I thought the big problem with selenium was when it was a powder and inhaling it. I would think that drying it out would be the last thing you would want to do. I have heard that you should just load all your junk prints into it for a day or so. This pulls all the selenium out and you can safely dump the rest.
Originally Posted by Louis Nargi
I personally only dump developer and used toner (processed as above) down the septic. The color chemicals and the fixer go to the local hazardous waste collection several times a year.