I think the "20th century" solution to letting many users in different locations run regexes would probably have been to write a cgi-bin script in Perl, and have users paste text into a box on an HTML form.

The results page generated by the script could have checkboxes to mark each suggestion as useful/not-useful/incorrect and a submit button, with this feedback saved in MySQL.

(I'm not sure whether this qualifies as "without ... services")