I found this book very helpful. In employing your internal “do not call” list, you go through itemized limitations that I suppose your members themselves have to stipulate, to conduct themselves according to this set of rules. One of the things you've mentioned is sequential dialing; marketers must not engage in sequential dialing.
How do you police something like that? I certainly have been told that's a frequent and common practice amongst telemarketers--maybe they're not members of your association, but telemarketers generally.