CarPro Immolube - one of the best options for a concentrated dillutable clay lubricant that Auto Obsessed offers! Find yours in 500ml and 1L concentrate sizes here: https://www.autoobsessed.com/search?type=product&q=immolube
This is what CarPro has to say about it:
"Introducing CarPro ImmoLube 500ml! An excellent new lubrication solution infused with a special mixture of surfactants and solvents designed for reducing friction while sanding, polishing, or claying painted surfaces. Its non-stick formula offers enough viscosity to reduce unwanted digging and marring. Immolube has no protective polymers, no unwanted gloss enhancers, and is easy to remove with a wash or Eraser wipe. ImmoLube works wonders while using sanding discs for spot repairs or denibbing and is an excellent partner for use with the CarPro Polyshave tools!
Dilutions: Claying 1:5 Wet Sanding: 1:10"