I certainly haven't and don't intend to. If Mormons want "secret ceremonies" that's their privilege under the laws and traditions of this name. You don't like it go to your own church somewhere else.
1 Corinthians 4:5 (New International Version)
5 Therefore judge nothing before the appointed time; wait till the Lord comes. He will bring to light what is hidden in darkness and will expose the motives of men’s hearts. At that time each will receive his praise from God.
I believe God is Sovereign. It is He that brings to light what is hidden in darkness. The darkness has been exposed by the Lord.
Any religion that isn’t 100% open about its doctrines, ceremonies, etc., is a cult. It’s fine if they want to do it since we have freedom of religion, but it’s not a mainstream relition.