Wainscot over a very damaged wall. Would this be a viable solution and how should I prep the wall before applying. I plan on putting white wainscot on with a “chair rail” and then just painting a nice color on top of the wall. Is there a brand of wainscot

Is TSP still the best solution or is there something else out there that is not so harsh? These walls I am about to wash are smoke filled. I also heard that putting a splash of vanilla in you paint will give it a great scent. Will this hurt?