If all the stuff you want to ignore is inside another folder, you can create another .gitignore inside that folder containing just * (i.e. ignore everything). Everything including the .gitignore file itself will be ignored.
This works really well to hide stuff from the public repo. The only downside is I don't think it's possible to then use source control on the ignored files in that folder. But if that's not a requirement it's probably the best way to go.