According to the Charlestown map and reviews, there aren't standout clean public toilets – both listed options at 91 James St and 17 Frederick St share a zero review rating and similar complaints about hygiene. The 91 James St facility is called out for being filthy with rubbish, stench, broken doors, and no supplies, making it far from ideal. Meanwhile, 17 Frederick St faces issues like persistent dirt, smells, missing soap and paper, plus dim lighting that amplifies the neglected feel. If you're after the 'cleanest' relatively speaking, it's a tie – neither shines, so perhaps avoid peak times or check the post's list for any user tips. For better options, consider private venues nearby, but stick to these for true public access in Charlestown.