My solution, which I've used for a long time and love, is the extension Tab Wrangler (https://chrome.google.com/webstore/detail/tab-wrangler/egnjhciaieeiiohknch

My solution, which I've used for a long time and love, is the extension Tab Wrangler (https://chrome.google.com/webstore/detail/tab-wrangler/egnjhciaieeiiohknchakcodbpgjnchh https://chrome.google.com/webstore/detail/tab-wrangler/egnjh...). It lets you set a time limit, and then closes tabs as they go that long without being opened. You can set up exceptions, and also tell it to not close tabs making noise. It's great. I open a bunch of tabs as I'm working on something. Then, when I've moved on to something else, those tabs magically disappear.