Specifics for Disabling Allocation Awareness Dynamically

This page Cluster | Elasticsearch Guide [1.5] | Elastic says that allocation awareness "settings can be updated using the cluster update settings API on a live cluster."

If I have settings like these from that page:

cluster.routing.allocation.awareness.force.zone.values: zone1,zone2
cluster.routing.allocation.awareness.attributes: zone

Do I put empty strings to those keys when I update the cluster settings?

Thanks