I would recommend the use of acetone for removing the release agent(s). More often than not, that agent is silicone. Initial sanding will only "drive" the silicone only deeper into the molded stock. I prefer to remove it first and then sand lightly.
Here is a stock on a muzzle loader I gave a facelift about 2 years ago with a "stone" finish. It also has two clear
satin top coats for glare reduction and added durability. This finish has held up very well and still looks good as new. Picture actually is a bit washed out and the color is more "hunter green" than what is seen.
There are about four or five different colors to chose from. I decided to stay away from camo patterns trying to stay away from the tactical look. BTW...the finish is easy on your chin when anchoring. This was a concern when I started with my project.