I e sanded varnish off stocks in the past... never again.. used loads of paper because it kept clogging.. made loads of dust.. just a nightmare for me...

For cleaning dust, just buy microfiber cloths from pound land.. get loads of them and keep them clean... you'll hear furniture makers and woodworkers call them tack cloth because they lift every speck of dust.

I done a lot of research on stock refinishing, especially beech as it's most common.. I remember watching a YouTube video where a guy claimed to have invented a stabilising liquid that you could apply to any wood which hardened the soft and the hard grain evenly, which then allowed you to dye or stain the wood perfectly... cant find it now