I didn't say nails are harmful, and I didn't say they don't work. I said that adding nails to soil does not imitate what plants encounter in nature, so if one is doctrinally willing to apply nails, industrially-processed iron, to soil, one should also be willing to apply other industrially-processed elements, fertilizers, to the same soil.
[Easy "home remedies" are not necessarily "organic", for doctrinal purists.]
Galvanized nails won't release their iron anytime soon, but they will release Zinc, which is usually also a good thing.
And any Cobalt, Manganese, and Nickel present in nails as "impurities" will also be good.