How did OP manage to get rid of ~/.mozilla? It's the only offending dotfile left in my $HOME and the stickiest. Until Mozilla fixes their 19-year-old feature request to support XDG [1], I couldn't find a workaround that wasn't a total hack.
Would this work?
https://github.com/queer/boxxy
[Edit] woops, I didn't notice that it is linked right at the bottom.