How can I update my tongue and groove wood paneling?

Painting it will do wonders and then add new ceiling and floor trim.

Is it knotty pine? May have a shellac finish you can use denatured alcohol to remove darkened finish. If not you can white wash it. Just thin down off white Oil based paint with paint thinner to the desired coverage or thickness you want. Do a little test area that's the best thing about oil base, if you don't like it just use pure paint thinner wash it back off before it dries.

just brush it or roll it on and wipe it off play with how much coverage you want, have fun

I am always a fan of painting it because it updates it so well, it is relatively inexpensive and it can really brighten up the room! You could also whitewash it, which would leave a sheer look to it. https://www.pinterest.com/pin/440367669800353425/

First try washing it. When dry, you can paint on latex paint, then wipe off with a sponge. The longer you leave the paint, the more will stay. Start with a scrap piece or in a corner.

Why not Stain it a colour so you can still see the grain.... Maybe graduate the colour or colours or give yourself a striped look.......Or use coloured Wax.

Hello, paint is the best to achieve a clean new look!

https://www.youtube.com/watch?v=SbQqPXPlaqQ

Really dont want to paint the walls.