Well, it depends on how you were doing it.
1. Moving trash:/ to trash:/ would result in an error; a protocol usually can't interact with another protocol unless there are additional arguments. Also, see 3.
2. Moving ~/.local/share/Trash to trash:/ could in theory work, but it depends on exactly what order things are done. The vice-versa as well.
3. Moving ~/.local/share/Trash into ~/.local/share/Trash can't be done because its the same directory. Duh

I do support the moving to main site thing, though.