Slow Macro - Hide Row based on cell value

I have a macro that will hide a row based on a cell's value inside that row. The problem is, it seems to take a very long time to perform this task. I know our work machines here are slow but is there anything that can be done to the code below to speed it up?

Screen updating and events are turned off.

Private Sub Hide_Accessory_Rows()
    'The following hides or unhides rows.  "x" = Row is Visible
     Application.Calculation = xlCalculationManual
    Application.ScreenUpdating = False
    Dim rRange As Range, rCell As Range
    Dim strVal As String
    Set rRange = Range("Hide_Rows_Test")
        For Each rCell In rRange
            strVal = rCell
            rCell.EntireRow.Hidden = strVal = vbNullString
        Next rCell
    Application.Calculation = xlCalculationAutomatic
End Sub

"Hide_Rows_Test" =Gen_3!$CB$17:$CB$626