It is time to describe the whole process to remove rust. To avoid an improper use (kids, etc.) chemicals will be encrypted ( you can PM to know them).
Read CAREFULLY: you MUST use latex gloves. DO NOT breathe fumes. Use "goggles".
Please operate as follows:
1) We have to prepare the first solution. Take a plastic bucket. Fill it with LW. You will add OA's crystals ( one soup spoon per 2 liters of LW or 1.5 glasses per 20 liters if you have to "preserve" a big item). Do not use more OA crystals, you will simply lose your crystals and you could have a yellowish "patina". LW's temperature can speed up the process ( I suggest to avoid high temperature, it could damage colour, don't forget you have an old item in your hands). OA crystals and LW must be mixed very well, you must have a solution with no visible crystals inside. Put your item in this solution for 1 hour ( no more than 1 hour) Every now and then mix that solution to avoid the precipitate. After one hour keep your "iron" ( remember to wear your latex gloves to protect your hands) and see OA solution's effects. Brush your item ( use a brush with plastic bristles). If you are satisfied you can start with the second step. If you want to remove more rust put it again in that solution and wait ( 1 hour), Then "work" again with your brush;
2) Second step. Now you are satisfied. Don't forget you have worked with and acid solution. That solution is still working ( your item is not in your bucket but our solution is working!).
Wash it with water (cold water). Prepare the second solution ( you need another plastic bucket). As you remember the first solution was acid. The second BASIC solution helps us to neutralize the first solution ( basic solution: water + SB). Wash your item in the second solution (use another brush to remove any yellow halos);
Now you can dry your item.
The first solution can remove rust and "improve" items' colour. Advanced collectors consider OA crystals as a Chemistry's miracle. Do not insert more items in the same solution. AN OBJECT AT A TIME! This process can take 1-6 hours ( more rust... more hours) and is specially indicated for fragile objects (with paint...). You can use it when you can't work with steel wool.
I suggest to start with an "iron" without value. I suggest a simple philosophy: "learning by doing". Improve your sensibility with a valueless iron and then you will start with your military items. Remember to protect some parts from these solutions ( wood, leather, fabric. etc.). Some collectors protect wood with wax, others do the same with a plastic wrap. Others think they can restore wood with OA solution, I do not agree.
DISCLAIMER: I will be not there to check your "first experience" so I will be not considered responsible for damages occurred to people or/and items. Remember all cautions I suggested, Keep away your children from these chemicals. Remember to dispose of the first solution according to your laws.