Adding urldecode to getURL array

Question

I need to add urldecode to the below function but unsure how to modify it so...

public function getAddFilterUrl($attribute)
{
    $filtering = $this->getRequest()->getParam('filtering', array());
    $filtering[] = $attribute->getAttributeCode();

    return $this->getUrl('*/*/*', array(
        '_current' => true,
        '_escape' => true,
        '_query' => array(
            'filtering' => array_unique($filtering)
        )
    ));
}

For example, the current URL outputted from the above is:-

/price_update/products/key/3b6f41cb95705740b8f46bbf1411a5e1/?filtering%5B0%5D=manufacturer

And what I want to output is:-

/price_update/products/key/3b6f41cb95705740b8f46bbf1411a5e1/?filtering[0]=manufacturer

I have tried modifying _escape in the array to no avail.