Living in the Scottish countryside we are beset with ticks. It's usually the tiny ones that sneak up on you. Being so small they are especially difficult to remove with the plastic tool bought from vets and chemists. I have discovered that dousing the little blighters in tea tree oil makes them give up their grip and fall off in entirety - I would probably give up in entirety if doused in the liquid too. This has worked for me on the last two occasions when I have found one on my person. This suggests that rubbing legs with the oil might act as a deterrent but I am mindful that fellow pilgrims in albergues can suffer ill effects from the smell so use with consideration of others.