How to best salvage off-spec filament? 2.85 mm measures to 2.97 !

I thought I had grabbed a great deal from the local Craigslist. My printer uses 2.85 mm filament through Bowden tubes and I've recently discovered that the stuff is nearly 3 mm and some of it probably is at least that large. Of course, I ignored the 3 mm label on the spool, figuring it was shorthand for 2.85 mm. Wrong. After getting far too many jammed Bowden tubes, I've given up using the stuff, but hate to throw it in the rubbish bin. I had considered investing in a home injection molding rig, but don't really have the need to mass produce models of that sort. My next train of thought leaving the station is to build a "step-down" extruder to push the filament into a 3 mm opening and pull it out of a 2.80-2.85 mm opening. I've seen DIY filament recyclers and DIY pellet-to-filament extruders, but this would not have to be quite as sophisticated, I believe. Does the community have any observations?