Why is it that TC manufacturers build TC that will leak and you must do messy work to revitalize them periodically? Does any manufacturer used truck cargo box methods? Think about it...cargo boxes...
My aluminum cargo boxes on the back of my camper don't leak...in fact I needed to vent one of them. If anything was put in the box that was slightly damp, canvas chair with dew on it the mildew would ruin everything...lucky me, I smelled it the next day and got everything out, washed and dried...then when I got home I installed vents top and bottom using 3/4 holes coverd by small ss clam vent covers used on boats...no more moisture issues and still no leaks.