Unless there is some compelling reason to tear out the walls

[Bruno1949]

like rewiring and replumbing everything, then don’t go through the effort and mess! Blown in insulation takes small 2″ holes above and below the fire stop in every outside bay, assuming you have fire stops in the walls. If you don’t have fire stops it’s one hole near the ceiling. Easy to do and easy to fix afterwards. And a LOT less mess!

Yes, a full tear out can give a better job, but it’s generally not worth the time, mess, and money to do. There is no clean and quick way to remove plaster walls. It’s messy, dusty, dirty, and expensive to get rid of the debris. I know. I’ve done it, but it was necessary. I wouldn’t do it again!