If you're swinging the weapon much at all while brewing, you're either amnesia'd or Doin It Wrong in hilarious fashion.
Anyway, as was pointed out, don't use KoR while brewing. If you're brewing with Excalibur for some reason, any of the magical WS are wildly superior - even Burning Blade is better. And if for some reason you're brewing with Excalibur and MUST use physical damage, use Vorpal.
But really, if that's where you're at with it, you took a jaunt onto the Bad Decision Expressway about four thoughts ago.