Most common knots and bends can be slipped. Slipping a knot is accomplished by adding an element to the knot that when removed leaves a space to ease untying the primary knot. Slipping is usually done with the tag end or a bight in the line. Foreign objects like a nail or smooth twig are sometimes suggested. As is a short hank of smooth cordage that can be pulled free. As illustrated in the images of the large blue rope.
The slipperiness of Vectran® and similar materials make it ideal for this application. And a pair of Slipping Tassels are included with each hoist.
Short hanks of braided Vectran® Validator-12 (bridle line)
One pair (2)
Colors will vary