bash shell function to clean up a PATH, and append . (complete with love note) Would probably work under zsh, even if $path would be cleaner.

fixpath

fixpath () {
  local IFS=:
  local newpath=''
  for i in $PATH; do
    [[ -d "$i"  && "$i" != '.' ]] && newpath="$newpath${newpath:+:}$i"
  done

  PATH="$newpath:/this_could_be_dangerous/:."
}
fixpath