How does move-staling work with bury-throws?

The reason normal throws don't send opponents as far after staling is because staling actually lowers the damage dealt rather than change the formula on how far an opponent is sent. The knockback formula can be looked at here showing that the percentage a move deals helps determine it's knockback distance. So staling on a bury throw will just make it easier (very slightly) to break out since getting out of a bury is based on your percentage when buried.