The sap should be water soluble and thus be removable with water based cleaners. The stains are a different story. They are most likely tannins and will not be easily removed, especially from light colored vinyl.
There is a product I use for all kinds of removal it is called brush and roller cleaner any paint store or hardware store will carry it.Don't know if it will work but I always start there when cleaning.(do a test spot to make sure it does not pull color out) Jim
I don't think you can get it off with water. I remember trying to water pine sap off my hands with soap and water, no good.
I would try naptha, paint thinner or turpentine.
These will not hurt the vinyl and should dissolve the sap.
