The really difficult part is getting all of the metal atoms which have shed too many of their outer valence shell electrons, ionized, lost affinity for similar atoms, formed inert molecules, and have precipitated out of the electrolyte to form a nice layer in the bottom of the battery case, to "jump" back up onto the plates and grids and take their former positions in the matrix. None of those additives explain how they accomplish that.
Here's an alternative. Recycle the battery, get your $4 scrap value for it. Save the $40 you would have spent on additives, add about ten more dollars and purchase a $55 NEW battery (with a warranty) if you need one. Let the recyclers reclaim and reconstitute the lead, nickel, and cadmium back into a useful form.