The only thing that I have used that will last forever for a baseboard is to use "tile." Moisture is going to degrade anything plastic, vinyl, or wood over a long period of time. I tried the tile idea and it worked until someone I know very well told me it was time to change the color !
I was just being a little facetious when I said "forever." I was considering doing some 1 inch tile and cap that with some sort of wood trim at the top.
I will have to experiment, unless anyone has ever done this?