Best way to prevent repopulation form after success submit?

Hello,

I use set_value etc in my forms. After I submit a form and data saved to database I wan't to prevent repopulation the form. Is there a better way then always create 2 forms in html view with checking for successful submitting and one time without set_value helpers?

I tried to

PHP Code:

unset($_POST); 


but that don't work.

My solution until now:

Create class MY_Form_validation and add a function:

PHP Code:

public function clear_field_data()
{
    $_POST = array();
    $this->_field_data = array();
    return $this;
} 


In Controller after success:

PHP Code:

$this->form_validation->clear_field_data();