One thing that seasalt will do if spotted by potential vendors is scare them away lol!
Try simple things that everyone uses to make you house more sellable, being super clean, fresh flowers, sunshine, lights on in darkened areas, windows open if its warm enough. Some put coffee on or bake cakes
Who gave you the advice to use salt and do a clearing? Have you been having spirit or ghost activity? Much better for seelling a house and not leaving any telltale signs are things like citrus essential oils and bell ringing, they space clear better than sage which cleanses or salt which protects. Mirrors, silver foil, crystals all will help too.