I have been using Danzac for about 5 years now, with a tumbler set-up just for it.
Before I put them in the tumbler, I have a clear plastic sports drink bottle with a pull up top that I dump the bullets in first. Then I put some 90% isopropyl alcohol in the bottle. Close the top and shake the bullets up for a few seconds. Then open the top and squeeze out the alcohol back into it's original container.
Dump the bullets on a towel and let them dry. Once dry, they are ready for the tumbler. This gets off any oil or wax that is on the bullets.
I have about 5 pounds of F-shot in the tumbler that I can put 500 bullets in and a butter knife tip of danzac. Turn it on for about 1 to 1.5 hours.
After that I have a plastic colander that I drilled some holes in to let the shot fall through but not the bullets. I dump the bullets and shot in the colander and work them back and forth to get rid of most of the shot. Then I dump all the bullets into a dry towel. Swish the bullets back and forth in the towel for about a minute. This gets all the residual Danzac off and polishes them nicely. They are then ready to be loaded.
Oh ya, when doing this I wear powder-free latex gloves and a dust mask. After the final swish in the towel, the bullets are good to go. When loading you very little on your fingers. It's very good stuff that doesn't build up like moly in the bore. These are my personal findings.
Lastly, I feel that it helps with consistent bullet seating. Yes proper neck tension and even case neck thickness is the main thing, but the Danzac gives the bullets a very consistent lubricity too.
.002" neck tension has always worked great for me with the coated bullets.
Hope this helps!