Glad you are taking the protection of your Vinyl seriously! Too many boat owners spend hours cleaning their interiors without thinking twice about moisturizing and protecting it ultimately shortening its life. With regard to Boat Bling's Condition Sauce we recommend it be used every 3-4 cleanings or after chemicals are used to remove tough stains or scuffs, and prior to long periods of storage. 1 quart usually lasts most customers a full season.
Give me a shout if I can help with any questions!
Zack@Boatbling.net