After chatting with development, the default deletion time on the Immunet client is 200 days. However, they have added an enhancement to build in a "Delete All" button in a future release.
Join us as we welcome our newest release, fresh out of beta, Immunet 5.0.
Come join us on the new version with a streamlined install and faster client: http://www.immunet.com
We look forward to seeing you!
Google's DNS is very fast FWIW. I use it on a few machines. There are rumors that it messes with anything that you have to go to Akamai for, but other than that, it works really well.