In the states where I am a bottle of Ammo or AK stuff is $14-$15. for 100 ml.
Many modelers use Gun Bluing solution. It turns metal tracks black not blue.
I use something called Oxpho-blue from Brownells. It's much more affordable and it comes in 4 oz to 32 oz sized containers.
https://www.brownells.com/tools-cleanin ... xpho-blue/

100ml = 3.38 fl Oz.
4 fl Oz. of Oxpho-blue is $9.99
32 fl Oz. is $59.99, I bought this size on sale last December for $48.
Just sharing a more affordable option that works the same.