How do I clean the diffusers on my Dyson Airstrait?

Ensure the machine is switched off, then slide the diffusers off the ends of the arms. Use a damp, lint-free cloth to remove debris and hair product residue, or a soft-bristled toothbrush for stubborn residue. Refit the diffusers once they are clean and fully dry — Dyson recommends not using the straightener without the diffusers attached. (Page 10)