We've been doing the $9 Amazon Basics fan with a good filter since wildfire smoke started really getting bad in the bay area, quite a few years ago now. We had a couple of big, expensive filter tower things, and they helped, but just a couple of the boxfans with filters duct taped on quickly and consistently annihilated PM2.5 and PM10 in our apartments.
Most surprising thing: all but one of those original Amazon fans is still running. They've had years of run time, at quite a bit higher stress than normal.