The logic of access review remediation is defined in the Standard Attestation workflow.
When an attestor requests remediation of a user entitlement, the Standard Attestation workflow:
Generates a remediation request (of type accessReviewRemediation) that contains information about the user entitlement requiring remediation.
Sends an email to the requested remediator.
The new remediator can then choose to edit the user, either by using Waveset or independently, and then mark the work item as remediated when satisfied. At that point, the user entitlement is rescanned and evaluated again.