I DO AGREE WITH EVERYONE ABOUT THE PUSHER.
I FIXED THE PROBLEM BY PURCHASING A WOODEN DOWEL THE SAME DIAMETER AS THE TUBE.
YOU CAN ROUND BOTH ENDS WITH SAND PAPER AND SOAK IN OLIVE OIL FOR A DAY YOU GET NO MEAT STICKING ON THE PUSHER AND NO AIR POCKETS.
HOPE THIS HELPS EVERYONE.