There are a few ways to clay a vehicle these days. We have a Fine Clay Bar, which can be used with car wash suds or the Boss Gloss detailing spray. We also have the Claying Rubber, which can be used with both of the aforementioned methods, or it can also be used with Three Way, our iron reactive clay lubricant. We don't recommend to use Three Way with the Fine Clay Bar, as the degreasers used can affect the clay - only use Three Way with the Claying Rubber.
If your wash suds bucket is still clean, add another capful of wash solution to it, then hit it with the hose or pressure washer again to get an extremely sudsy mixture going. If the wash water is dirty, pour it out and start fresh with a double dose (2 cap fulls) of wash mix, then froth the mixture up nicely. Use this suds mixture as the lubricant for your clay medium.
We've used the Fine Clay Bar with Boss Gloss here because it's just a bit easier to get in and around the different areas of the tank and other sections, plus we had a good indoor area to work in.
Knead the Fine Clay Bar into a small, flat piece, then spray some Boss Gloss liberally onto the sections of paint you want to clay, then also spray some Boss Gloss onto the clay bar. Begin gently rubbing back and forth, then up and down. You will feel and hear the contamination if it's present on the surface, as it will be rough. Gently rub the clay over the surface until it becomes smooth. Don't apply any pressure to the clay - they work better with light pressure. Knead the clay as needed, and lubricate each subsequent section of paint with plenty of Boss Gloss.
Once the section you're working on becomes smooth, wipe excess Boss Gloss off with a Big Softie cloth and move onto the next section.