Lye baths and electrolysis tanks eliminate or at least reduce the amount of elbow grease necessary to get a pan stripped. Neither lye nor oven cleaner spray will do anything to rust; a 50/50 vinegar/water soak will, but is still comparatively labor intensive. Steel wool will not hurt cast iron, but is not aggressive enough to effectively remove rust or crud, and is usually reserved for final touches like dark spot reduction.
Lye won't hurt iron, and it's common to leave pieces soaking in lye baths even after the crud is removed as it inhibits rust formation. Soap and water are all that's necessary to rinse it completely off after it's done its job. For those who say it's "toxic", I also usually remind people that if they have eaten green olives, bagels, canned mandarin orange slices, or lutefisk, they have consumed a food processed with lye.
You can spend literally all day on youtube watching videos that purport to be the best or only way you should do things. The potato and salt thing might work, but so would oil and salt, or a stainless steel scrubber, S/S wire brush, steel wool, etc. Kind of seems like a waste of a good potato, IMO.
