End the trickle or at least make it more costly for the defenders
Eg : say 600 troops to keep the battle going to the next round
I hate getting trickled for 12hrs and coming away with nothing buts it's great when the defender trickles for 8hrs and gets his times wrong and he did it all for nothing
But there needs to be some kind of realistic calculation to it.
More In the way of trying to make numbers count
Defenders all ready get a three to one raitio on attackers so then also using trickle make it very near impossible to take a castle these days.