It's reasonably good - I tested it for Polish swearwords, it misses some no-nos, such as "alfons" (which stands for "pimp"), I actually submitted this :)

It reminded me of this major company https://en.wikipedia.org/wiki/Osram whose name happens to be "future tense conjugation of verb >to shit<" (a spot-on match, and the website correctly detects it) :)

It was founded in 1919 when the website didn't exist yet