diff --git a/source/guides/recruitment.rst b/source/guides/recruitment.rst
index 24b6fe758d6234138ea4e39d7e30025dfa846640..ad93526818263ba9c827275270a3d8892a06740c 100644
--- a/source/guides/recruitment.rst
+++ b/source/guides/recruitment.rst
@@ -117,3 +117,33 @@ you to set up appointments for the participants:
     Castellum only detects appointment collisions for connected resources! In
     other words Castellum allows you to save various concurrent appointments if
     the session doesn't have a resource connected.
+
+.. _recruitment-cleanup:
+
+Cleanup open list in recruitment
+================================
+
+The open list in study recruitment can become quite large and noisy if you are 
+waiting for many responses and/or failed to reach many potential participants. 
+Therefore, Castellum provides a cleanup feature:
+
+1. Scroll down to the end of the open list in recruitment and click on 
+   **Cleanup**
+2. Decide if you want to cleanup the *complete* open list (**All**) or 
+   only those potential participants whose status is marked as 
+   **Awaiting response** for more than 10 days. The third option allows you to 
+   run potentially modified recruitment filters on the list (**Mismatch**). This 
+   allows to cleanup those who do not match anymore. A click on either of these 
+   buttons will start the cleanup process.
+3. After cleaning up the affected potential participants will be moved to the 
+   **Excluded** list with the additional tag **Excluded by cleanup**. This may 
+   allow you to reconsider contacting some of them.
+
+The open list also gets quickly populated by mail recruitment (if set up) with 
+many potential participants with the status **Awaiting response**. Thus, 
+Castellum additionally allows to cleanup by mail batches:
+
+1. Go to the **Mail** tab in recruitment and select an appropriate entry of the 
+   **Previous mails** list. Select **Cleanup**.
+2. Confirm that you want to cleanup all potential participants of the mail batch 
+   who did not respond.