I only feel the need to use this Blue, Fine Grade version of the AutoScrub system. This Sponge, the AutoScrub Pad, and Optimum Clay Bar are what we use for Step 3 of the Decon process. You can use soap and water, detail spray, or a dedicated lube like Glide for this "mechanical" part of removing contaminants that are embedded in the surface of the clear coat. I find myself using this Sponge more than the larger pad or clay bar. It's much more convenient and contours to the surface. So if you were to pick one, I'd pick this. You could do your whole car with it. If you drop it, rinse it off, and keep going.
I'm not sure how many years I've had my original pad, but it's more than 5 years old. So despite the initial expense, these last a really long time. I've certainly spent more on clay bars over that time frame than I have on this. I equate this to being about 90% as effective as clay, but much quicker and easier to work with.
You could watch the video above if you'd like, but I use this like so. This is the third step of the decon process.
When new, the pad needs to be broken in by cleaning the glass.
Immediately after "chemically" decontaminating the car with CarPro Iron X, rinse the car thoroughly. I use deionized water.
I spray 7:1 diluted Glide liberally, soaking the panels you want to decontaminate. I usually start on the glass then work my way from top to bottom.
Use this Sponge, AutoScrub Fine Grade Pad, or Opt-Clay bar on the surface of the paint to remove the stuff you don't want there. Glide is the lubricant we need to reduce marring and scratching during this step.
It really doesn't matter if Glide dries on the paint because you are going to be polishing, but I like to rinse off after I've done a few panels. It will dry a bit streaky if you let it.
Rinse thoroughly and dry the car. I always rinse with deionzed water.