What are the scientific methods for repotting and pruning orchids?

Orchids generally need to be repotted, have their growing medium replaced, and have their roots pruned every year. The method is as follows:

When repotting an orchid, the potting medium should be thoroughly dry. Gently knock the plant out of the pot and remove the soil, being careful not to damage the roots. Then rinse the roots and leaves with clean water, cut off any rotted or broken roots, apply sulfur powder to the cut surfaces, or soak the damaged roots in potassium permanganate solution for half an hour to prevent pathogens from invading the wounds. Then place the orchid in a cool, shaded spot and wait until the roots soften slightly before repotting in fresh medium. Since orchid leaves emerge from the pseudobulb only once, and old pseudobulbs do not produce new leaves again, the orchid leaves should not be cut off arbitrarily.