My two vacuum insulated stainless steel cups will keep my coffee hot for about an hour, and drinkably warm for another hour and a half. I run hot water into them to preheat the metal before pouring. But, I think now temperature vs time needs to be graphed. I have a recording thermometer and Excel.
Get a pack of bristle pipe cleaners. Shove one down the drain and twist it a turn or two. When you pull it back out, it will have a nasty glop of hair, soap, and skin oil attached. Throw the whole conglomeration away. Enjoy a free running drain.
I rescued the annoying squeaker from a shredded toy and occasionally sound off with it when the dogs aren’t paying attention. They come running.