DM is a tool, no doubt, but auditing can be done without a meter, and probably to better effect, IMO. Meters are cool, I own three, but the only time I ever use them, in my practice, is to check rudiments: is the needle dirty? No? Then start major process. Is the needle dirty? No? Then end session. For everything else, I'm looking at the person in front of me. If you're addressing something that they have interest in (and thus, charge on, per theory), and they are willing to tell you about it, who gives a fig if it reads?