Well, I don't know the exact chemistry of the products, so I can't directly speak to their efficacy.
However, if you could break it down into their mineral content, then you can determine which works better by seeing which product's mineral (simplifying it to a single mineral) is sturdier, and will thus have more scrubbing power.
That assumes a uniform distribution of two minerals.
To really found out, in a mineralogy perspective, you'd also have to determine the concentration of each mineral in the product, and use the concentration, with the hardness, to calculate which is more efficient.
This is a common lab question for all college introductory mineralogy labs.