Can't Encrypt Backups

Month or so ago encrypting a backup. I don't use encryption, but just this once. It's a month later and I have forgotten the password I used. But, when I try to tell iTunes I don't want to encrypt anymore it demands this arbitrary and long forgotten password to just QUIT ENCRYPTING. I have no desire to restore the encrypted backup, I just don't want to encrypt future backups. This has created a situation where I cannot backup anymore.

I ran across a procedure on the web where I can throw away part of my phone's data and somehow iTunes will hear this and quit encrypting. I didn't give my phone a password I gave iTunes a password so I'm leery of using this suggestion. If I could backup I would give the procedure that makes no sense to me a try and if it created issues or didn't do what the procedure say it will do I could just restore. But I can't backup so I can't defend against something radical going wrong. If I can't resolve this I can never backup again.

Anybody know a way out of this dilemma?