Repellents are just a temporary solution. You also need to reapply them (and not forget to reapply them). I don’t think that will work for you in the long term. Many of us on the forum make cages out of fencing to protect the trees when they are young. I think that is a better approach. Here is a thread that discusses cages.
Really fencing in the orchard is the best solution but I don’t have a fenced in orchard. I do have deer pressure and I managed to live with it but I have some damage each year.