undef *PaCkAGe; does not work for me -- That's the first thing I've tried anyway.

Right, try something like

{
    no strict 'refs';
    for( keys %PaCkAGe:: ){
        undef *{"PaCkAGe::$_"};
        delete $PaCkAGe::{$_};
        delete $::PaCkAGe::{$_};
    }
}
[download]

MJD says "you can't just make shit up and expect the computer to know what you mean, retardo!"

I run a Win32 PPM repository for perl 5.6.x and 5.8.x -- I take requests (README).

** The third rule of perl club is a statement of fact: pod is sexy.

use Symbol(); Symbol::delete_package("PaCkAGe") instead of undef *PaCkAGe; will remove all symbols of package, but you surely won't be able to remove all side effects of a package unless the package itself supports that.

But if you fork (or start new ithread) before loading the package, then ending that process/thread will almost certainly remove the package completely.