I use: 10 yourprivateproxy proxies for ScrapeBox (actual posting), and I get my public proxies from thebigproxylist (I pay 5 bucks for access). You can filter proxies on the latter website by how recently they were live (e.g., last day vs. last hour) - then I check them with ScrapeBox to filter out ones that are dead. This process is much faster than having ScrapeBox go through its cockeyed list, as most proxies that it finds don't even work - it finds 10 every 10-20 minutes - the ones from thebigproxylist are not as cockeyed - about 25% of the proxies on the last hour list work.