I have seen an instructable on this and I thought I could make it easier for you... http://www.instructables.com/id/Ultra-Lightweight-Backpacking-Spice-Kit-only-1oz/
The same principle but the closing of the straws is with fire... That makes it faster and probably more secured.
This are waterproof and you can seal them again if you have some heat source when you are camping (like fire! match, or lighter).
have fun and enjoy it!