I've never heard of Quebec Moss before
If you can't be sure it hasnt been treated with something its best to err on the side of caution and avoid it altogether. The best moss to use IMHO for brazilians is sphagnum. It works well to keep an adequate humidity level, but I found it too difficult to work with as a substrate. It's virtually impossible to spot clean (the only thing visible are the uric acid accumulations), and BRB's excrete alot more liquid urine that many other species, which is impossible to clean up after as well. I think its more suited to humid hides. The best loose substrate I have found for these guys is slightly dampened Carefresh. You can easily spot any messes, it holds humidity very well, permits burrowing, and is environmentally friendly to boot
My favourite substrate though to use for these guys is newspaper or papertowel. The ink gets their chins a little grungy looking sometimes and it looks dreadful, but its super easy to maintain, very cheap, and serves the purpose very well
Hehehe... ok I just babbled off and away from your question. Hope you found something in there that was of some use