cleanlib32
Remove lib32 packages from your Archlinux box
...Ok, but how does it work?
Each time you run it, it will look for lib32 packages currently marked as "installed as dependency for another package" in the "Install Reason" (pacman -Qi <pkg>) that are not needed anymore by any other pacakge and then will uninstall them, with user's approval.
You'll probably want to run this script more than once as, by uninstalling one package, another installed as dependency might be not needed anymore.
P.S.: packages not marked as "installed as depedency" will not be listed neither removed.