I'm beginning to think the only thing to do is get another phone number and guard who its given out to. That creates major confusion with people trying to get ahold of us, we can't put a recording in with the new number, for obvious reasons.
Getting another phone number should not be a big deal to your husbands customers. Sheesh, it happens all the time. Get the new number, email ALL your husbands clients, then CALL all the clients he handles regularly. It will give him a good excuse to talk to them, and your customers WILL change your contact info as soon as they get notice.
No big deal, really. Don't overthink this one.

to anyone to NOT make these calls.