my @cleaned_AoA1 = map { grep length, @$_ } @AoA1;

##</code><code>##

foreach (@AoA1) {
   @$_ = grep length, @$_;
}

##</code><code>##

sub make_scrubber {
   my ($aref) = @_;
   return sub { [ grep length, @$aref ] };
}

my $iter = NestedLoops(
   [ map { make_scrubber($_) } @AoA1 ]
);