In many churches they use the words ‘plead the blood of Jesus’ over this or that. I am wondering why the Latter-day Saints don’t use those words.
Why would we? That phrase is primarily from so called Charismatic circles. The particular wording of the phrase is not Scriptural. It is purely a cultural fabrication — from a culture that takes great efforts to separate themselves from us.
That said, I don’t see such as being wrong or evil, just something we’re not accustomed to. It’s just a particular group’s wording of a concept that Latter-day Saints also happen to believe in. One of my all time favorite orators (Elder Neil A. Maxwell) declared this very doctrine but simply used different words in his speech entitled Apply the Atoning Blood of Christ (Oct 1997 General Conference).
Brothers and sisters, Christ paid such an enormous, enabling price for us! Will we not apply His Atonement in order to pay the much smaller price required for personal progress? (see Mosiah 4:2). Being valiant in our testimony of Jesus, therefore, includes being valiant in our efforts to live more as He lived (see D&C 76:79).
So, if you find something particularly meaningful about those particular words, then by all means go ahead and use them. But the concept and principle is much more important than the specific verbiage used to apply the principle.
But one thing I will try to do is pray more frequently for the Atonement of Jesus Christ to be applied to my life, my sins, my weaknesses, and my eternal progression. I hope you do too.