Yup, no stain, nothing but ferric nitrate crystal/denatured alcohol mix and then blushing with a heat gun. I was amazed also. It was a grade 2 maple stock from Pecatonica River, i.e., about 50% curl.
The ferric nitrate crystals dissolve pretty well in the denatured alcohol. You get a yellow-reddish solution that you brush on the stock liberally. Let the stock dry very thoroughly before blushing with the heat gun. Some of the other forum members have used this solution to good effect also... IIRC MeteorMan has posted some pics of a Tennessee rifle stock using it.
IIRC, I did a second brush-on, blush cycle with the solution on this stock, although in hind sight I don't think it was absolutely necessary.
I wore rubber gloves and did it outside, however, I didn't notice any fumes, etc. It all was very tame and easy. I actually found it easier than stain. Also, since you can mix up small quantities as you go, you can avoid having to deal with the large quantities of leftover solution.