Periodical scrubbing, one pool at a time

Do you know if there is an easy way to enable periodical scrubbing, such as started by cron, but only if no other scrubs are active?

The reason I want to do this, is that I have a disk with two partitions, where partition 1 is a member of pool A and partition 2 is a member of pool B. I do not want both partitions to be scrubbed at the same time.