If you have any questions about the misappropriation of scripture verses under the guise of sanctifying fundamentally evil praxis, please read Dan's blog, Somebody Needs to Say It. It is fundamentally impossible to be "in Christ" and to pray this prayer, regarding anyone. Please note who is speaking such words in the Psalm, and how the Psalmist responds with love, prayer and goodness:
1 Do not be silent, O God of my praise.
2 For wicked and deceitful mouths are opened against me,
speaking against me with lying tongues.
and attack me without cause.
even while I make prayer for them.
and hatred for my love.
let an accuser stand on his right…"
The ones praying this prayer are those with "wicked and deceitful mouths" not those who serve the LORD our God! If these verses don't make it clear enough, consider how the psalmist ends:
26 Help me, O LORD my God!
Save me according to your steadfast love.
27 Let them know that this is your hand;
you, O LORD, have done it.
28 Let them curse, but you will bless.
Let my assailants be put to shame; may your servant be glad.
29 May my accusers be clothed with dishonor;
may they be wrapped in their own shame as in a mantle.
30 With my mouth I will give great thanks to the LORD;
I will praise him in the midst of the throng.
31 For he stands at the right hand of the needy,
to save them from those who would condemn them to death.
We serve a God who blesses us and who calls us to bless others with our mouths and lives. (Cf., James 3:6-18) If we "pray" this prayer – which is truly a curse, we will be among those who are "wrapped in their own shame as in a mantle."