naval jelly is way less concentrated than dedicated blue remover. naval jelly is made for remivng rust from polished surafces while leaving th epolished surface intact. blue revoer is designed for stripping off everything. kinda like rubbing compound vs paint stripper.
You are correct on the concentration... I have found however that it works just fine as long as you give it time to do it's thing! For me it was easier to get without either a long drive or a waiting a week for an internet order.
Take 5 packets of a fruit Kool-aide mix (unsweetened..this stuff is sticky enough on it's own that you don't need to make it worse by adding sugar). Mix all 5 packets with 2 to 3 oz of water until it becomes a thick paste.
Make sure to have a good work surface that you don't mind getting stained (because this will stain anything it touches but steel), and spread evenly and liberally. Let sit for anywhere from 15 to 20 minutes. Then, wash off with soap and water.
You will find that the bluing on nearly any type of weapon will come CLEAR OFF! No fumes, no toxic chemicals. This can be done in an Apartment or an enclosed shop with 100% safety, and is totally safe for human contact. Just, be careful because this stuff stains like NONE OTHER, including skin! But, beyond that, it's perfect for cheap bluing remover that is safe to use around the house and with the younger ones around if you're getting them into the shooting sport!