when I use caustic, I use a strong caustic and do a longer rinse/soak. But, my equipment never builds up huge deposits. Generally, I prefer a percarbonate+ carbonate mix over caustic for washing.
You don't need very much if you use it as a longer soak. It's not that much, but think about what you're doing. Just like you said, saponification and other action of OH- ions. You don't need a huge amount, better to use time + smaller amt.
It does work as a sanitizer, but it's overall more effective when doing caustic to use that plus acid wash. Reason is that acid wash will catch anything else, and will leave it more friendly to food.
Iodophor at 25 ppm works great. Maybe you can get some from a brewery or dairy?