I would stick with what works for others rather than waste time trying unproven methods. Not saying that there ar not other ways but this is what has worked for me for years and believe me I have tried just about every thing.
AF works well but you have to heat the horn almost to the point of not being able to touch it, just before the blisters. Apply the AF and let it sit, it is going to come out lighter than it looks. Let it sit, I usually wait until it cools, then wash it off. Warning; if you have already rounded your horn the heat will/may bring it back to the original shape, so leave the sizer in it. Also make sure there is no oil on the horn, that included from your fingers, I have also found that if you use a scraped finish and All the scraping is not in the same direction you will get two different colors. If it is not what you want after washing repeat the process until you do, If you just don't like it just scrape it off, I wouldn't worry about getting it to thin. I have never used anything, like a Base, on the horn after the AF. Shoe polish or wax works well although will lighten with time. If you get to much dark shoe polish on it use a Netural wax or floor wax to take off the color.
RIT dye works well too, once again as explained above with heat. I also use Oil based leather dye, again with heat.
With whatever you use heat the horn to open its pours, it may not go very deep but it will penetrate a bit.
May be more than was asked for.
Tim C.
PS: I do use other stuff, Tea and Paint being two, but this is the basics. TC
