Open the file containing the IP addresses in SublimeText and go to Find - Replace....
Make sure you have the RegEx selector enabled - it looks like a .* sign next to the search field.
For IP addresses that look like this: 99.7.83.38 enter the following regex: \b(\d{1,3}\.){3}\d{1,3}\b.
For IP addresses that look like this: 99.61.204.91/32 enter the following regex: \b(\d{1,3}\.){3}\d{1,3}\/\d+\b
Then click the Find All button (on the right) and copy them into a single blacklist of IP addresses.
After that you can leave only unique values. To do this, open the menu Edit - Permute Lines - Unique. Depending on the length of the list it may take a few seconds or minutes.
Save the file and use it for your needs.
PS. This answer about choosing IP addresses is also good.
