To clean your beads in raw or varnished wood, simply use a soft cloth slightly dampened with lukewarm water and mild soap. Wipe dry immediately. Never put them in the dishwasher or washing machine, as this will cause the wood to swell and crack.
Yes, raw wood beads are ideal for DIY personalization. You can use acrylic paint, gouache or Posca markers. For a long-lasting finish, remember to apply a protective varnish (matte or gloss) after painting. If the bead is intended for a child, be sure to use only toy-safe (non-toxic) paints and varnishes.
A raw wood bead is sanded but has not received any surface treatment: it is matt and ready to be painted or oiled. A varnished bead has received a protective coating (often gloss or satin) that makes it more resistant to stains, humidity and wear, while enhancing the wood's natural color.