Do not ask or interrogate demons for information. Example: Mark 1:25 Jesus told the demon to hold his peace. Jesus didn't want to hear what the demons had to say, likewise believers should not want to hear also what demons have to say ! Evil spirits are liars. In John 8:44 , Jesus revealed that the devil is a liar. Demons under his dominion are also liars. To ask demons for information to find out there name in order to cast them out is asking a liar to tell the truth. The Holy Spirit guides you into all truth. Speaking to demons to gain information in order to cast them out is a denial of the ministry of the Holy Spirit . Do not consult with familiar spirits. In Deuteronomy 18:9-12 , we are warned to not do things that are an abomination to God. The word "consulting" in verse 11 means to ask or inquire . A familiar spirit is an evil spirit (demon) who is familiar with the person. Asking demons for information in order to know what to cast out is consulting with familiar spirits , which is an abomination to God .Interrogating demons for information is an unscriptural practice.Demons can send curses at others. If you allow demons to speak through a person , they have a means to release curses at those who are present or those who are not present. Curses are released through the mouth according to James 3:10. By allowing them to speak , one is giving them opportunity to release curses. Prolongs the deliverance , allows demons to control the person when they are speaking , and is not edifying to anyone . When demons are coming out slowly , they usually come out with a yawn, sigh, burp,belch, or light cough. When demons are coming out rapidly , they come out with flurries of coughs. Demons can come out so forcefully in some cases that person vomits. Demons can also come out through a release of air through the anal, nose and vaginal passage .. Remember demons are real , not figment of imagination of a person mind.