Hi Gayle, here is an easy one.
I used to do large amount of hot water until I found an unclogging tool that works every time in minutes. I see it in every big box home store, Walmart and Amazon on line. It looks like a short rotor rooting device. (Snake). Works every time. I don't know how to clean it but then that was a problem with plunger. Good luck! Mine was more than a plunger but much cheaper than a plumber.