While you’re at Lowe’s be sure to pick up a pint of plunger oil, which will help keep the plunger lubricated and prevent the plastic from degrading like this. It’s not expensive and it’s not hard to use. All you have to do is lick the plunger clean after each use, allow it to air dry, then apply a small dab of the oil, and rub that in with a soft natural fiber cloth. A plunger can last you a life time with proper care.