Does it need to be reapplied every so often? Or just a one time application?
So far, I did my initial application last summer. Did another this fall before winter, and will do another this spring. I'm going to do mine twice a year, just after the winter and just before winter. Might be overkill, but I don't want to deal with these rusting issues and we are in the snow/salt belt.
You could probably get away a yearly application down there.
Just make sure you rinse them out good and let them dry before your initial application and you should be good to go. Like @
CoronaRaptor stated, they are probably just full of mud and or sand now and need to be rinsed out. The whole job shouldn't take more than a few hours the first time, and then the future touch-ups will be easy.
Periodic checks throughout the year to make sure the tape hasn't fell off is a must for the whole thing to be effective.