You are right, that's a frustrating result... Let's try a more forceful and specific approach... Please run these commands as **root**:

1.  **First, ensure the `/dev/sdb` entry is gone**
    ```bash
    echo 1 > /sys/block/sdb/device/delete
    ```

2.  **Next, explicitly remove the device from both SCSI hosts it appeared on:**
    ```bash
    echo 1 > /sys/class/scsi_device/1:0:0:0/device/delete
    echo 1 > /sys/class/scsi_device/2:0:0:0/device/delete
    ```

3.  **Finally, rescan all the relevant SCSI hosts.**
    ```bash
    echo "- - -" > /sys/class/scsi_host/host0/scan
    echo "- - -" > /sys/class/scsi_host/host1/scan
    echo "- - -" > /sys/class/scsi_host/host2/scan
    ```

4.  **Check the result:**
    ```bash
    cat /proc/partitions
    ```