I have been in the process of scrubbing my full list of absentees recently.  

These are ones I am still scrubbing:8.

Just scrub it off first with a brush, then bleach as above.

They help input leads, pull comps, transcribe voicemails, get your marketing out week in and week out without fail, scrub your lists, remove bad addresses from list, build your lists,  they even offer a sales team to help you call your leads for additional fees.

Scrub the list make sure you're not sending 50 letters to the same person. 

I then scrubbed the list for properties I believed would work for me.

Pulling the data was a little difficult, and it still needed to be scrubbed.

I suspect they have paid a 3rd party to scrub negative reviews.  

Be sure to scrub your list after each mailer to get rid of any that have sold already or told you to stop contacting them.

@Jacob Hanson If you want to be legal for ALL TELEMARKETING:Register as a telemarketer on the federal website https://telemarketing.donotcall.gov/then scrub your list against the people who have registered for the do-not-call (DNC)you can't call a cell phone, regardless of whether or not it is registered with the DNC.