Parts Washer cleaner

I don't know about other areas, but in my neck of the woods the oil change place I go to will allow me to dump anything I bring in down their drain basin. I couldn't believe it the other day when I had a couple gallons of used antifreeze and the guy told me to just dump it in where they drain the cars!! Mineral spirits are petroleum based if i'm not mistaken and could be added to used waste oil with no problems, at least at the place I go to!!! Geof