Set::CrossProduct does exactly that. You have to build one loop to get the strings, though.

You can also make up something with glob.

Update: here's an example with glob:

#!/usr/bin/perl
use strict;
use warnings;

my @l = (
    [1, 2, 3],
    [4, 5],
    [6, 7]
);

my $glob = join '', map {'{'. join(',', @$_). '}'} @l; 
local $\ = "\n";
print for glob $glob;
__END__
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