I'm faced with the identical problem, but ours hasn't gotten to the point it needs to be done right away. One "do it yourself" solution I've read about/considered is rather barbaric, but faced with replacing the window, might be worthy of consideration? The plan, in a nutshell, has you breaking the inside layer of glass only - leaving the outside pane intact. From what I understand, any etching will have normally have occured on the inside glass, which should allow for the outside pane to be cleaned.
If I go this route, I'll put a drop cloth in place prior to breaking the window, making for an easy cleanup.
This should leave me with an installation as good as any tempered setup, and clearly (pun intended) better than plastic.....
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake