When I finish seam sealing a tent I usually have some goo left over so when I feel like it I coat something else.
With it I have coated the stitching in some of my boots, did that on a backpack (more to reinforce the stitching than waterproofing it) striped the bottom of a couple of mats and coated mason line too.
The mason line I get is cheap and weak, but once coated it is rather strong and waterproof. This ends up as zip pulls, straps and side guylines, the non load bearing type.
Inspired by how we used to dry spaghetti soon after the harvest back home, I dry that line the same way.