Sorry but posts like this really annoy me.
What is this "local chemical supply house" of which you speak? Is there actually such a place? Because I don't think they exist. Maybe it's a Canadian thing; do they have those in Canada on the corners right next to the coffee shop? Because I have lived in Ohio and in Texas, and in Montana, and I have never found a single place, even in the entire Dallas/Ft Worth metroplex, where a regular person can actually go to and buy chemicals off the shelf. I have never seen a chemistry store. I have called lots of chemical companies, but unless you are a business looking for a supply of chemicals for some industrial application, they basically hang up on you. It would be great if there were stores like that; if there are, by all means point me to them. But it really annoys me to read on the internet when people say "Oh, just trot down to your nearest Acme Chemicals To Go and buy a 25 pound pail of ammonium thiosulfate" as if it was that easy all over the world.