I did purchase this product 2 days ago and was using it to remove heavy rust on some parts of my custom bike.
Surprisingly it works really well and all i did is just leave all the parts in 1 container and soaked it with Rust Combat liquid and leave it over night.
Some rust is still visible but using wire brush that can be cleaned really easy after i soaked them over night and I'm reusing the liquid for the next parts i want the rust to be remove.