All the import is doing is making the class available to your code. If the method is static then use
ClassName::method();
If it’s not, use
$obj = new ClassName;
$obj->method();
If the method is used in multiple controllers and is specific to the controllers, you could add the method to your Controller class instead of making a new component.
In hindsight, I believe the components directory is already automatically imported by Yii, so the import call is likely redundant.