Remove Sublist Line Items - Customer Specific

I found the following code in another post (shout out to Sklett):

function clearLineItems(listId)
{
    for(var i = 0, count = nlapiGetLineItemCount(listId); i < count; i++)
    {
        nlapiSelectLineItem(listId, 1)
        nlapiRemoveLineItem(listId, 1);
    }
}

Is it possible to modify this code to remove line items from a specific customer's sublist? My objective is to strip all addresses {addressbook} and eventually contacts {contact} from a specific customer record. Any help would be appreciate as I am new to JS & scripts. Thanking you in advance for any assistance.