Clean inside an OU contacts - PowerShell

Hello,

I need to import contacts every night of a business application.
They are either deleted, created or update contacts.

My import command works perfectly. All this goes to a specific OU Contacts in AD.

My question is whether there was a command to update all this or just to empty the OU.

thank you,

import-csv c:\test.csv -Delimiter ';' | foreach { new-mailcontact -alias $_.Alias -name $_.displayName -ExternalEmailAddress $_.eMailAddress -OrganizationalUnit “domaine.fr/architecture/utilisateurs/Contacts”}