Dry robes need very little cleaning as they shed dirt readily, and tend not to retain odours. However, if you do need to remove dirt the first port of call would be to wet-sponge wipe your robe.
If you choose to machine wash your robe, to maintain the waterproof properties, follow these steps:
• Use a mild detergent without fabric softeners.
• Turn your robe inside out
• Wash on a gentle cycle at a low temperature.
• Air dry rather than using a tumble dryer.
• Occasionally reproof with a water-repellent spray, to restore protection.