I often read your posts as they are really good. I feel I am in exactly the same boat as you- at the same stage of trying to beat this horrible odor. I am sorry that Champex didn't fully take the odor away, I thought it was working for you. It didn't work for me either but I tried it only for a month.
As for TMAU and the low Choline diet. It rarely works for people with TMAU. i.e. people say it reduces the odor a lot but I think like me you are looking for odor totally gone. If you have come round to thinking you have TMAU then it's best to get tested. You can put your name down for Dr Pretti at the Monell Centre in Philadelphia (long waiting list) or there are other ways to be tested, in the U.K. and States. I don't know where you live. If you like, we could keep in contact, either by private email or could chat msn or on the phone sometime. I have exactly the same condition as you and I tried the low Choline diet for 6 months with chlorophyll and charcoal. Chlorophyll makes me smell worse, I don't know why, maybe because it's made from seaweed, other people have mentioned he same.
I have been tested 3 times for TMAU. I got one result positive for Secondary TMAU and then regretably posted on Body Odor sites and said BINGO! You don't have to smell of fish to have TMAU you can smell of anything and many people then went on to be tested. I also remember the biochemist who tested me talking to me on the phone saying - Now you have your positive result, i.e. wink wink you have what you wanted. Basically I didn't want to be tested positive if that wasn't really the cause. Then I was given Antibiotics and tested twice after that negative. The docs were very happy, my notes say I am cured and all along, no change in odor at all! I know another person that had the same. Basically real Primary TMAU is when you have the genetic disorder from childhood and it should be strictly a fish smell. We have fecal odor at the moment. There is a doctor in the U.K. that is testing urine, (a DNA test can not be questioned but would only show primary TMAU anyway) he is always testing people positive. Basically it's really difficult to explain all of this in a post but one thing is for sure that TMAU is incurable and the diet hardly ever works. If you have secondary then they say it is bacteria in the gut that produces FMO3 and the liver isn't able to clear this toxin hence it comes out through the skin. Now if it's gut bacteria then it must be curable and Secondary TMAU seems to me to be a mild form of TMAU that has been kind of made up in the last 10years. If Doctor Pretti is reading this, and I know he reads these sites sometimes I would really like to hear his view on Secondary TMAU and if he accepts it as a legitimate condition? I don't know if that has been explained well!
So get tested by all means, I can understand why anyone would want to be tested. A low choline diet would omit egg yolks, green leafy vegetable, spinach etc, all fish but some say fresh water fish not salt water is o.k. People usually eat turkey etc. Basically you need a certain amount of choline to live. And if you don't provide your body with it in your diet then you body will actually make it. It is so fundamental to life.
I don't know about you but common sense prevails that if it smells like poo then probably it's got to be something to do with poo! Therefore it could be a problem with the colon intestines and any number of different problems with the other systems of elimination, liver, kidneys, lungs, lymph. Each person could have a different problem.
It took me a few years and experience to come to this conclusion and I don't mind being shot down in flames by anybody that believes I am entirely wrong. But I have never read of anyone stopping odor on the low choline diet and TMAU is an incurable dead end road.