small regexp help

[rusi]

Well it seems that we are considerably closer to a solution to the GG double-spaced crap problem.

Just wondering if someone can suggest a cleanup of the regexp part

Currently I have (elisp)

(defun clean-gg () 
  (interactive)
1  (replace-regexp "^> *\n> *\n> *$" "-=\=-" nil 0 (point-max))
2  (flush-lines "> *$" 0 (point-max))
3  (replace-regexp "-=\=-" "" nil 0 (point-max)))

Which I spell out as:

1. Replace triplets of empty lines of the form

>
>
>

with only 1 (because this is an actual blank line and not a GG-crap line)
However then it gets mixed up with the others so put some strange string:
"-=\=-" as replacement

2. Remove the pure
> 
lines

3. Remove the strange string.

Not very robust since the strange string could occur in the text.
So what are the more proper regexp solution(s)?