I did 10 days. Honestly, I liked how I felt getting a break from porn and jackin off. The issue is that the feeling of doing it is also nice. I often want to take a break again but dam..its not easy. The last 2 months I've been jackin more than usual.
Pretty regularly go a month without, I think longest was 3 1/2 months. Worth it if you are busy with other things and don't have a steady GF but if you won't last as long just a warning.