for my $phrase (@phrases) {
   for my $filter (@filters) {
      my $pos = 0;
      for (;;) {
         $pos = index($phrase, $filter, $pos);
         last if $pos < 0;
         substr($phrase, $pos, length($filter), '');
      }
   }
}

##</code><code>##

my ($filter_re) = map qr/$_/,
                  join '|',
                  map quotemeta,
                  @filters;

for my $phrase (@phrases) {
   $phrase =~ s/$filter_re//ig;
}          

##</code><code>##

use Regexp::List qw( );

my $filter_re = Regexp::List
                ->new(modifiers => 'i')
                ->list2re(@filters);

for my $phrase (@phrases) {
   $phrase =~ s/$filter_re//g;
}