This is a simple script using the Twilio Python module to retrieve Recordings within a certain date range and then delete them.

delete-recordings.py

from datetime import date
from twilio.rest import TwilioRestClient

account = "ACxxxx"
token = "xxxxxx"

client = TwilioRestClient(account, token)

recordings = client.recordings.list(after=date(2012, 1, 1))

for recording in recordings:
        print recording.sid
        recording.delete()