I tried a find/replace:
e.g.
find: page_^#
Replace: page_^&
It adds another "page" word in front, I guess because ^& found the word "page" in the "find" field. Am I doing it wrong?

I also tried replacing "^$ ^$" with "^$ ^$" with the aim of removing all double spaces between words (but not between full stops and words), but when I do that it tells me that that ^$ is not a valid character for find/replace.