Do spammers not call Twilio numbers?

I assume the spammers buy "known active real person phone numbers" from somewhere (probably the awful carriers themselves), so it might be less likely for them to find a new Twilio number. But as soon as you give the phone number to some company that sells (or accidentally leaks) their customer data, that number will be burned too.

I don't know about calls, but I definitely get spam SMSes on my persistent Twilio SMS numbers.

This is a simple and neat idea. I'll try it on the weekend.