Birchwood-Casey products are available at most sporting goods or gun stores, or now you can order them direct. Their web address is http://www.birchwoodcasey.com.
Rosewood fingerboards should not be treated with the gunstock oil; instead they should be treated with a high grade of lemon oil, or even better, with Ernie Ball Wonder Wipes Fretboard Conditioner. These wipes really work.
For cleaning, try using the same high grade of lemon oil to clean the entire neck, both maple and rosewood fretboards, and again our Wopnder Wipes Fretboard Conditioner. If the neck is very dirty, you can use a small amount of Murphy's Oil Soap, diluted 3:1, to clean it. Keep in mind that if the dirt has gotten into the wood, it cannot be removed except by sanding it down, which we do not recommend a lot of. It is better to keep it clean in the first place. Washing your hands first helps!
On an maple neck, some discoloration after many hours of playing is normal.