CkEditor - setting allowedContent to true doesnt disable ACF

Hello,

I want to disable ACF on ckeditor, and as many post and documentation suggest, i am setting allowedcontent to true by below ways, still its filtering out my html.

CKEDITOR.editorConfig = function( config ) {

config.allowedContent = true;

// also tried CKEDITOR.allowedContent = true; and CKEDITOR.config.allowedContent = true;
 };

I trying to insert my custom tag as below, in my plugin code.

CKEDITOR.plugins.add('MakeCPBold', {
    init: function (editor) {
        editor.addCommand('MakeCPBoldCommand', {           
            exec: function (editor) {              
                editor.insertHtml('<CP:CP_B>Sample Content</CP:CP_B>');                               
            }
        });
        // Create the toolbar button that executes the above command.
        editor.ui.addButton('MakeCPBold', {
            label: 'Make CP Bold',
            command: 'MakeCPBoldCommand',
            icon: this.path + 'images/makeabbr.gif',
            toolbar: 'Basic'

        });
    }
});

insertHtml just inserts the "Sample Content" and filters custom tag CP:CP_B. Replacing tag CP:CP_B with any known tag(like strong) works fine.

Please let me know if I am missing anything.

I am using latest version of ckeditor 4.4.1. Also tried version 4.4.0 and  4.2

Thanks