clear blob cahce of all web apps using powershell

Below PowerShell script loops through all the web application in a farm and clears the blob cache. 

$WebAppColl = GET-SPWebApplication

foreach($WebApp in $WebAppColl )

{

                [Microsoft.SharePoint.Publishing.PublishingCache]::FlushBlobCache($WebApp)

Write-Host "Flushed the BLOB cache for:" $WebApp

$$WebApp.Dispose()

}

$WebAppColl.Dispose()