RonDon - I don't know if there's a source on-island, but if not I'll be using 4-Star Cargo to ship some from mainland USA; I'm in the UK at the moment and can only get 350ml of 0.5% solution for about £8.50 - that's very expensive compared to the USA market which has veterinary 10% solution in larger quantities and this can be diluted and applied to clothing and other items. In your case you could just take it with you in your baggage.

p.s. 7 washings is a lot to do in 2 weeks If you hand-wash the treatment will last even longer, since it is mechanical and not chemical action that removes the protection.