I think that you are correct--there is not an effective treatment for ETD. My older, experienced doctor, and the freshly-trained doctor who subbed for him on vacation gave me the same treatment--pseudofed to dry up the head, and Mucinex, which worked a little. I also gave up dairy products and white-flour stuff, which are mucus producers.
I cured my ETD (muffled hearing, earpopping, and tinnitus) by going to a swimming pool everyday last summer, going underwater, turning every which way, blowing bubbles out my nose, and humming loudly underwater. This got chlorinated water into my Eustachian tubes. When I got home, i laid down on the bed with my infected ear up, and blew up a balloon, which got enough air pressure into my tube to drain it (balloon trick was the only useful info I got from a doctor on the internet). It took 3 weeks, but the problem is gone.
A better treatment would be to get hypertonic saline into the Eustachian tubes, which would clean it and shrink the tissues. Even though I invented a highly effective method of flushing sinus infections, I don't know how to get saline to the ear, and maybe someone else could help you out.
http://www.medhelp.org/user_journals/show/2322