Question on how to use clearex

I bought some clearex salt remover for my current grow. The directions say to acheive a minimum of 80-90% run-off. I was just wondering what that means.

It means after ya put the clerex in the soil and let it soak. Ya want to run a shit load of water threw the soil to make sure ya rinse it all out.

I'm guessing it means that when you pour a gallon into the top of the pot, you want to see more than 8/10ths of a gallon coming out the bottom. In other words, the soil in the pot needs to be almost completely saturated and unable to absorb any more water.