You may wish to 'purge' the clone databases which have been created from a given image. You can run this from any machine which has the PowerShell cmdlets installed, and where the caller has access to perform SQL Clone operations.

Connect-SqlClone -ServerUrl 'http://sql-clone.example.com:14145'
$image = Get-SqlCloneImage -Name 'ImageName'

$clones = Get-SqlClone -Image $image

$elapsed = [System.Diagnostics.Stopwatch]::StartNew()

"Started at {0}, removing {1} clones for image ""{2}""" -f $(get-date) , $clones.Count , $image.Name

$clones | foreach { # note - '{' needs to be on same line as 'foreach' !
    $_ | Remove-SqlClone | Wait-SqlCloneOperation
    "Removed clone ""{0}""" -f $_.Name ;
                    };
"Total Elapsed Time: {0}" -f $($elapsed.Elapsed.ToString())