1. Mark well the URLs thou dost wish to spare 2. Establish a schedule upon which thou desires the tabs to be slain 3. Tarry not, for the task shall be accomplished without further ado Thus, thy browsing experience shall be kept neat by this noble extension
I hacked this together because I wanted it. It's possible this functionality already exists - but not with the name tab slayer.
I believe the permission are pretty reasonable, it needs access to your tabs to close them. I can open source the code if people would rather audit + build from source themselves.
I would probably add a feature if you asked, and would be even more likely to do it if you bought me a coffee :)
have a great day!