In the <Advanced Search> page:
1) Select the proper Forum/Forums to be searched
2) In the <Keyword Search Terms> box, type this:
+"Celeb Name" -" Celeb Name"
(same thing, with a <Space> between the " and the name)
3) Click the <in subject> button
4) Set the <Date Range>. I use weeks, the maximum # of returns is 150, if you get 150, keep reducing the rang a few weeks at a time until you get less than 150. This keeps you from missing any Threads.
5) Default is 25 results per page, I normally set it higher.
Example ... I didn't know who Minka Kelly was, so selected Actresses, Models, and Miscellaneous (in case she was a correspondent for E! network or something, like Maria Menounos).
I got 131 results, each result was one Thread, NO REPLIES (except one, several celebs in Thread, Title was "Name 1,Name 2,Name 3 ...
Notice there's no <Space> before the Names, so
left the replies too. You could add -",Name" to the <Keyword> box to filter out those replies.