We live outside Portland, OR, and we need to know what we can use to clean the trailer without destroying it in the process. We have a 1 year old Scamp that spent the winter outside under a cover, but has been uncovered since our first trip this spring the last week of March. We have what looks like it might be dark greenish/black moss or mildew or mold growing on the trim strip around the middle of the trailer and on the top...basically anywhere there is a crack or crevice or ledge it can grow on. Are we going to hurt the finish if we use certain products? How do we get this "stuff" off?