Plastic dip will work, though it's a mite thick. Also can be difficult to do a neat job.
Stuff is commonly sold to coat handles of tools (sold in Big Box stores and often local hardware stores). Same stuff, just much higher cost per ounce, is often used to coat electrical wire at the connection points to prevent corrosion. Usually can be found in electrical area of Big Box stores, hardware stores, and recreational marine stores for sure. The stuff sold for electrical use usually comes in a small can with a brush in the cap. Makes for a little easier use. Color selection is usually limited to red, sometimes yellow. Stuff is a bit messy to use, and industrial in appearance.
On thick webbing, I prefer to zig-zag the cut end to prevent fraying. On thinner webbing, I double the end over and stitch.
Back in my military days, our web belts had brass ends formed over the webbing end. I'm sure those brass ends are available somewhere, though don't know where.