While I think there are some extreme cases where spanking doesn't work (like in the adoption of a child from an abusive background), I believe Christian parents ought to uphold the Bible in their homes as the outline for Christian parenting and discipline.
Therefore, the Rugged Mountain Man and I spank for foolishness and here's why:
Proverbs 22:15 says, "Foolishness is bound in the heart of a child; but the rod of correction shall drive it far from him." NASB
One of our children seems to have a particular bent for saying foolish and untactful things in group situations. (I'm not talking about one instance. I'm talking about a pattern of behavior over several months.)
We've determined that this daughter is old enough to obey and heed the warnings that we've given to her. We've found ourselves in uncomfortable situations, unsure of whether or not to pull her aside or let it lie until later.
By common consent, the Rugged Mountain Man and I have moved into another stage of discipline. She's been warned. If we catch her in the act of this particular type of foolishness, I might say, "Blossom, that is enough of that kind of talk." The warnings have usually gone unheeded (generally because she believes we will not follow up since she's in public.)
(Perhaps you're wondering why it took us so long. It seems like the problem was only occasional for a while. It has only grown. Combined with our uncertainty, the problem happening most often outside the family circle, our slow identification that it was something that WAS foolishness and that it really did need more than a "stop it," we are now working on a solution. And yes, this is why parenting keeps you humble.)
After the discreet, "that's enough" goes unheeded, we remove her from the room and administer a loving spanking. Additionally, I like to ask the questions,
"What did you do wrong?"
"Why is that wrong?"
"What will you do next time?"
I encourage her to try again next time. I believe she will develop self control and stop this foolishness. God will help her! She CAN use her tongue to build up, instead of for foolishness or tearing down.
I want to encourage you not to brush off foolishness in your children. Deal with it head-on while the issues are still small(er). Our children will not be a delight to us if we do not correct them in Godly ways.
"Correct your son, and he will give you comfort; He will also delight your soul."
Proverbs 29:17, NASB
Many folks are missing the delight and comfort of their children, because they refuse to discipline with God's effective methods. (I think we can all imagine how NON-delightful a teenager running their mouth tactlessly in public and at home is to a parent.)
I challenge you to use the Bible to outline your parental discipline. Obey God and calmly and lovingly spank your child(ren). There will be good fruit.