What a great idea! And if you really must express your opinion knowing it is just going to fuel the fire, type it up in an e-mail and e-mail it to yourself!
I used to head up a kids basketball program at our school, one year a parent made the most hideous, rude comments on the end of the year summary. This parent was a notorious trouble maker, did nothing but complain yet sat on their uknowwhat and did NOTHING. My partner in the program wanted to respond sooooo badly, she was so disgusted! So I advised her to write the letter and then e-mail it to me and herself. She did, it helped diffuse her anger and gave her the outlet to "speak her mind" without stooping to a lower level. 3 years later I still have a copy of the original complaints and the e-mail "response" in my desk. I will occassionally e-mail her an excerpt of it and we chuckle over it even to this day!
but when my hubby and i was in las vegas last time, we went to a comedy show. One of the guys was talking about something like you brought up and he would say
"good for you" and we all knew what it meant, so he told some funny funny jokes and then at the end would say "good for you"