We have a moderately sized AD installation with approx 1000 employees and maybe 1800 valid computer accounts (servers, PCs, virtuals). Because we replace desktop hardware on a 3-4 yr cycle, cleaning up old computer accounts is a necessary task that usually get's put off. We currently have 3200 accounts!). We have a robust process in place for identifying unused user accounts and disabling/deleting them, but nothing in place for computer accounts.
We know about tools like oldcomp, powershell, etc and we even have a windows batch script which uses dsquery and dsrm to handle this, but we've not actually production-alized anything.
My question is simple - What process do you use to clean up these accounts?