Enable scavenging on all dns zones using Powershell

So I needed to enable scavenging on all reverse zones for a customer. All forward and most reverse zones were done but not all. Since this was a Windows Server 2012R2 server I knew, that every cmdlet I might need was available.

$IPofDNS = '192.168.66.21'
$Zones = Get-DnsServerZone | Where-Object {$_.IsAutoCreated -eq $False -and $_.ZoneName -ne 'TrustAnchors'}
$MissingZones = $Zones | Get-DnsServerZoneAging | Where-Object {$_.AgingEnabled -eq $False}
$MissingZones |Set-DnsServerZoneAging -Aging $True -ScavengeServers $IPofDNS

But what if I have enabled scavaging but want to update which servers will scavenge?

$IPofDNS = '192.168.66.21'
$Zones = Get-DnsServerZone | Where-Object {$_.IsAutoCreated -eq $False -and $_.ZoneName -ne 'TrustAnchors'}
$WrongZones = $Zones | Get-DnsServerZoneAging | Where-Object {$_.ScavengeServers -eq $IPofDNS}
$WrongZones |Set-DnsServerZoneAging -Aging $True -ScavengeServers $IPofDNS

And now all my zones have scavenge enabled and the correct DNS server specified.