We enabled Flow on several pages on Polish WP, and Tar Lócesilion reports that the abuse filter isn't working.
The page to check: Dyskusja Wikipedii:Flow/Brudnopis (Flow tests)
Examples:
"Ja też lubię placki !!!!!" ("I like cakes/pies" - a frequent spam string)
https://pl.wikipedia.org/w/index.php?title=W%C4%85tek:Sm3w00lgha53fswv&topic_showPostId=sm4y78eb5nfwxrky#flow-post-sm4y78eb5nfwxrky
"zajefajnie" (something like "fucky cool")
https://pl.wikipedia.org/w/index.php?title=W%C4%85tek:Sm3w00lgha53fswv&topic_showPostId=sm47h78xurdwjkod#flow-post-sm47h78xurdwjkod