If the lady in question is in for some adventure and doing something out of the ordinary before it's too late she will get over the toilet trouble within 4 or 5 days.
My first days on holiday I am often disgusted about this and that but as I go I just get used to it and the novelty of it all is much more important to me than the discomfort. When I get tired I just upgrade to a better place and rest before I go on.
Advise:
Don't go to dirty toilets short after a main meal. The nausea might cause vomits or even vomiting like it happened to me sometimes.
Have wet napkins with disinfectant with you to clean your hands after you have touched those doors and handles. Have someone holding your bag and coat because it's hard to balance if you need to hold your stuff.
Yes for sure empty the pockets of your trousers and roll them up because you don't want that dirt on your clothing.
Have paper napkins or toilet paper in your pocket at any time.
If your wife is already concerned about the condition of the toilets I think you should also tell her there are places where toilets are not individual, like in many places in China.
Now I know that men stand brotherly next to each other while urinating, but for me as a woman to put my pants down and squad in a row with other women is quite uneasy. Sometimes even with doors open and people passing by. It's a nightmare, all the noises and smells that should be kept private are shared. Then you are at a airport or big shopping mall and bathrooms have doors but many Chinese women don't care to close them. Makes me think of Scandinavian young women at the end of the seventies and eighties when I used to camp a lot. The women would walk around naked in the big rooms where bathrooms and toilets where as if they were at home or in the sauna. But it was not home it was Spain, Portugal and Greece where I saw it. And there people there don't do that.
In Cambodia, Laos and Vietnam people also do it on the street or along the road when the bus stops. Me and my friend would walk away looking for a bush to hide or just use the sarong to make a wall. The locals would laugh and probably make lots of jokes. Just different outlooks and that makes travel really interesting. Afterwards I can even laugh about my own embarrassment.
Just do it before it's too late.Your plan is great and if your wife doesn't want to go with you it's a pity, but don't stay at home dreaming about what could have been. Just look for someone else or do it on your own. You will be sorry if you miss this chance.
You can also convince her to start with a month away trip. Take a plane somewhere and go back home with the train, or do the train thing only a part of the time. If she likes it the second step could be made more adventurous.
Good luck
