Just in case a Dooney owner is interested I contacted customer service and their response is below.
Thank you for contacting Dooney & Bourke. We apologize for the delay in responding to your email. For the canvas portion please use sodium free seltzer water along with a soft bristled toothbrush and a mild ivory bar soap. Do not saturate the purse; only spot clean in a gentle circular motion.
Sincerely,
Customer Service