Is there any way to turn off "index replicas" for an existing bucket?

We have a small 2 node setup that we're basically using as a reliable memcache cluster (moxi + replication). We're not using any of the 2.0 indexing stuff, just simple kv store. Right now it's disk bound with about 10 million docs (may of which are very small and have short expire times).

We're beginning to suspect index replicas might has been a mistake give that we're not using any index. - Can we turn it off? Will it make a difference?