I use Breaders Choice too. We have 2 trays (& 2 indoor cats) and I change it every second day on average. We use a scoop & flush the poo - mostly i do all the kitty litter duty but I'll try to con DH into doing it 'cause we're TTCing.

For users of other types of litter - I wouldn't flush the poo unless the kitty litter bag said it was flushable.