Spiritual workers can and do call and command in the name of Jesus Christ and it is quite effective. An example of such use would be:
"Rebbecca Janet Green, I Command You In The Name Of Jesus Christ To Shut Your Mouth And Stop Your Back-Biting, Gossip, And Slander!"
One can either say this alone or do this in conjunction with other work, such as burning candles on their name-paper or picture.
What I would recommend doing is to take a bible, hold it to one's chest and with the other hand point to either their picture or to the direction in which they live while saying, "Rebbecca Janet Green, if you have any love for Jesus in your heart you will immediately stop your back-biting, gossip, and slander of me and come and apologize to my face". If that person is a Christian and has any love for Jesus in their heart then they will immediately stop the hateful things they are doing and will come and apologize to you. If by chance the person doesn't, then they are not a Christian. One then needs only to command them in the name of Jesus Christ and dominate them.
If you are bold enough and yell your command in the name of Jesus Christ to their face, they will usually get very angry and storm off. They probably won't realize it, but Jesus shut their mouth.
Keep in mind that calling and commanding in the name of Jesus Christ can be used in many situations. It is especially good when a person is not treating one right.