Trailor boat so I am guessing you are not going to be offshore. Try it and see what happens. I have no idea if that will work. On the other hand - if the price of new halyards is not a huge concern - replace them becasue you will feel better. Another important factor is the age of the boat. If over ten years I would say replace them - though fresh water halyards can last much longer. Also,
lines that are easy to handle are much better. My thoughts.