A video making the rounds on TikTok contains a pretty good method for ridding your microwave popcorn bag of pesky un-popped kernels. It starts with a woman telling you to refrain from touching the slit at the top of the bag, because “that slit’s there for a reason,” implying the slit was designed to help the popcorn eater rid themself of kernels. The real “reason” for that slit to exist is to allow steam to escape during popping, but you can use it for kernel-removal purposes.
… The procedure for removing the kernels is simple: Invert the bag, shake it, and the small un-popped pieces of corn fall through the slit, leaving the popped corn behind. If the slit’s a bit small, pull it open a little bit. The slit trick works.