"Pleading the blood of Jesus" is not Biblical. It comes from the word of faith movement and has no power, they are just words. It is Christ in us Who answers prayers and comforts us.
This is a Pentecostal idea scripture taken out of context and used as a mantra to ward of demons. We see no example of this in the scriptures.
This belief of "pleading the blood of Jesus" over things is a good example how one phrase has been taken out of context and used to mean something God never meant.
Revelation 12:11
"11 And they have conquered him by the blood of the Lamb and by the word of their testimony, for they loved not their lives even unto death."
Colossians 1:13
"13 He has delivered us from the domain of darkness and transferred us to the kingdom of his beloved Son,"
The scripture referring to the blood of the Lamb has to do with the death and resurrection of Christ that did away with sin. The martyrs died proclaiming the death and resurrection of Christ, their faith in Him gave them the power by the Holy Spirit to endure death.
I cannot tell you the number of times and the number of beliefs that have been concocted from the Pentecostal movement that were nothing more than snatching one verse from its context, snatching another verse from another context and putting them together to make them say something God never said.
Beware of powerful sounding ideas using scripture twisting to make a new age paganistic magical idea.
Rather than pleading the blood, we ought to be seeking to obey Christ.
James 4:7
"7 Submit yourselves therefore to God. Resist the devil, and he will flee from you."
If someone is called to be a martyr for Christ they can plead the blood all day long but they will still die. It does not matter whether they say these three words, it only matters that they obey Him even unto death.
Cleansing a home from devils is a matter of prayer, not an unbiblical mantra.
It is good to be watchful in the terminology we use, making sure it is Biblical within its context.
The power in the blood is not something we say, it is something Christ did on the cross. He shed His blood for sinful man that whoever wants to follow Him will be saved because His sacrifice was accounted to all who desire to be changed into a new creation by Him.
Hebrews 7:25
"25 Consequently, he is able to save to the uttermost those who draw near to God through him, since he always lives to make intercession for them."
James 4:7
"7 Submit yourselves therefore to God. Resist the devil, and he will flee from you."
We resist the devil through prayer and obedience to God, not through any mantra.
Colossians 1:13
"13 He has delivered us from the domain of darkness and transferred us to the kingdom of his beloved Son,"
Devils flea when we resist them in prayer to our Heavenly Father in the name of Jesus Christ, but only if we are born-again.
James 4:6-8 "6 But He gives us more grace. This is why it says: “God opposes the proud, but gives grace to the humble.” 7 Submit yourselves, then, to God. Resist the devil, and he will flee from you. 8 Draw near to God, and He will draw near to you. Cleanse your hands, you sinners, and purify your hearts, you double-minded.…'"
It is good to take every phrase we hear in church gatherings today and search the scriptures to see if it has a Biblical basis. Many ideas within the church today do not have a scriptural basis, they have been concocted by unsaved pretenders taking ideas from paganism and adding them to the body of Christ.
We live in a world that thinks if we have a "good idea" that sounds plausible we should use it to make people feel safe. Many of these good-sounding phrases and words come from the devil to distract us from the truth.
Rather than seeking God in truth through prayer and Bible reading, people will just throw out the phrase thinking they have pleased God. Its a sort of fast food mentality that requires no prayer or scripture study.
Walking with Christ is a battle continually against evil. If we want to be Spiritually safe we must pray and study His Word to know Him. If we know Him we will not be fooled by clever sounding phrases.
Seek Christ not popular phrases snatched out of their context.