Since growing double-digit Bass is not part of my management plan, I prefer having a pond full of 10-12" largemouths. However, I do cull BG quite regularly, and simply give em' a toss over the dam, still kicking...I would do the same with the Bass were it beneficial to my goals, although a 12" Bass might find its way into the skillet.
I understand that this issue may be difficult for some, but I am of the belief that being a good pondmeister may well involve making decisions that are....uncomfortable. I think by necessity everyone draws their own line in this regard. If we didn't, how could we fish with live bait?