Eliminating super squeaky floors from above?

We finally have a chance to deal with a tenants super squeaky floor. It’s an old original pine plank floor over an old plank subfloor and it squeaks TERRIBLY. Like it will wake you up if someone walks in the room above.

When we had the chance years ago and were working underneath we ran resilient channel and added sound insulation between the joists. But this squeak is still terrible so now we will attack it from the top.

New carpeting and padding will be going down so we don’t care about damaging or aesthetics of the wood floor and are open to whatever it takes to get rid of the squeaking- it’s that bad.
Of course we’ll try screwing down boards, though this can be tricky over areas with no joist below.
One idea was to lay a layer of plywood over everything but I’m not sure what the best approach.
Also open to flooring guy recs if you have someone who has successful fixed this before.

Thanks for any advice, I’m sure I’m not the only one who’s dealt with this.