Evapo-Rust works well and is environmentally safe. It's water based and after soaking the nail, just rinse it off and Evapo-Rust can even be used as a rust-inhibitor! Just dip a clean object in Evapo-Rust and allow to air dry to prevent rust for up to two weeks. https://www.theruststore.com/Evapo-Rust-Gallon-P1C1.aspx I used it on a wood burning stove that was rusted and it worked as advertised.