In 6.0 the fonts settings are a bit different. Now I do:
cd /etc/fonts/conf.d && sudo rm --verbose 01-trisquel.conf && sudo rm --verbose 59-droid-serif-fonts.conf && sudo rm --verbose 60-droid-sans-mono-fonts.conf && sudo rm --verbose 10-hinting-slight.conf && sudo ln --verbose --symbolic ../conf.avail/10-hinting-full.conf && sudo ln --berbose --symbolic ../conf.avail/10-sub-pixel-rgb.conf gsettings set org.gnome.settings-daemon.plugins.xsettings antialiasing 'rgba' gsettings set org.gnome.settings-daemon.plugins.xsettings rgba-order 'rgb' gsettings set org.gnome.settings-daemon.plugins.xsettings hinting 'full' gsettings set org.gnome.desktop.interface font-name 'Sans 9' gsettings set org.gnome.desktop.interface document-font-name 'Serif 9' gsettings set org.gnome.desktop.interface monospace-font-name 'Monospace 9'