I have a .net exe called foo.exe I open foo in a hex editor (HxD) and search for myString. I do not see it.
I open foo.exe in ILSpy and was able to find myString.
I do see human readable text in the hex editor but I think the .net strings are encoded some other way.
Some background is we have a client site that switched servers on some 10+ year old code and the server configuration was hard coded. The old server was left online during testing and the issue was not found until 12 hours into production.