Remove SC_TICKET entries from the Core database using Sitecore PowerShell Extensions.

CleanupTickets.ps1

<#
    .SYNOPSIS
        There is an issue with the authentication ticket cleanup for certain versions of Sitecore. Run this script as a scheduled task.
        
    .LINK
        https://kb.sitecore.net/articles/615926

$ticketIds = [Sitecore.Web.Authentication.TicketManager]::GetTicketIDs() | 
    ForEach-Object { $_.Replace("_", "") }

$countRemoved = 0
[Sitecore.Diagnostics.Log]::Info("CleanupAuthenticationTicketsScript: Total number of authentication tickets to process: $($ticketIds.Count)", $host)
foreach($ticketId in $ticketIds) {
    $ticket = [Sitecore.Web.Authentication.TicketManager]::GetTicket($ticketId, $true)
    if($ticket) {
        if([Sitecore.Web.Authentication.TicketManager]::IsTicketExpired($ticket, $false)) {
            [Sitecore.Web.Authentication.TicketManager]::RemoveTicket($ticket.Id) > $null
            $countRemoved++
        }
    }
}
[Sitecore.Diagnostics.Log]::Info("CleanupAuthenticationTicketsScript: Number of expired authentication tickets that have been removed: $($countRemoved)", $host)

RemoveSCTickets.ps1

# https://kb.sitecore.net/articles/345947
# https://kb.sitecore.net/articles/615926

Import-Function -Name Invoke-SqlCommand

$connection = [Sitecore.Configuration.Settings]::GetConnectionString("core")

$query = @"
DELETE TOP (100)
  FROM [dbo].[Properties]
  WHERE [Key] LIKE 'SC_TICKET_%'
"@
$records = Invoke-SqlCommand -Connection $connection -Query $query

$query = @"
 SELECT COUNT(*)
  FROM [dbo].[Properties]
  --WHERE [Key] LIKE 'SC_TICKET_%'
"@
$count = Invoke-SqlCommand -Connection $connection -Query $query -As Scalar