If you poked the middle of the bung under the battery it might have just dislodged the blockage. If you have the time, please double check it's gone. Technically it should land on the floor. The one under the brake servo has a cable running through it, I pushed mine down with a screwdriver as far as I could so there was plenty of room for water & leaves to escape.
When I finished mine I got a bucket of water and poured it onto the windscreen to simulate a heavy downpour. The water and crud should pour out quite quickly.