If it is not structural, get yourself some red devil spackle and fill it with that. Then sand. Baking soda works, I have used it in the past, but I don't any more. If you use it, watch the smoke coming off of it when it kicks. If you get it in your eyes, you will know it! It stings like hell. Its also good to wear saftey glasses if you are doing that just in case it pops. I have seen that happen and get in a couple guys eyes. The docs hate scraping it off an eyeball. Kicker will do that too if you use it on thin CA sometimes.