It's been discussed all over the web for a long time, but the consensus is make sure to get Hydro
PHOBIC Fumed Silica and
Progressive Epoxy Polymers is a good source.
I can recommend them as I have been buying their stuff for years AND you will get an MSDS (Material Data Safety Sheet) with it to make your own decisions in regards to any safety precautions.
A turkey baster works great for refilling empty Frog Fanny bottles, BUT a better option is buying SEVERAL 8-12oz clear plastic flip top squeeze bottles in the camping section of your favorite store.
Filling the larger squeeze bottles with the baster is less messy than filing the small Frog Fanny bottles, then you can use the squeeze bottles to refill the Frog Fanny bottle. The other great thing about using the squeeze bottles is you can keep a few full bottles with your extra gear in the car and refill your Frog Fanny bottles as needed, just before you head to the water.
FWIW – I like a softer LDPE plastic bottle with a flip top. That allows me better control when I squeeze out the Hydrophobic Fumed Silica. I got mine @ REI but there are many sources if you look around.
You will also want to store your bulk Hydrophobic Fumed Silica in a secondary container like a Rubbermaid bin, with the turkey baster because no matter what you think, it gets messy refilling.
In regards to Amadou, the stuff WORKS!!
Despite the misconception among many that Frog Fanny dries & treats your fly, any fly to be treated with Frog Fanny or an equivalent should be dry FIRST, for maximum effect. There are many Amadou fly drying patches you can buy, but after a while the Amadou (which is a fungus), can get beat up and fall apart.
For that reason, I buy sheets of Amadou from NON fly-fishing internet sources (people use it as a fire starter and to make hats) to repair any of my fancy high priced fly-fishing Amadou patches when they get beat up. You could also just buy a piece of Amadou and keep that in your pocket.
In regards to drying your fly first, Cortland makes a product called
Dry-Ur-Fly which is a super fine silica desiccant crystal that works fantastic for drying out soaked flies before an application of Frog Fanny. I have been using it forever. If you use it after a squeeze between the Amadou, your fly will be about as dry as if you just took it out of your box.
Good luck!