And to then avoid reproducing code (which probably negates the advantages of not using a temp variable) (untested):

@array1 = @array1[slicer(@array1)];
@array2 = @array2[slicer(@array1)];

sub slicer {
    grep 
       { $_[$_] =~ /keep these/ }
       0 .. $#_;
}
[download]

    -Bryan