You do a non Freesat scan, and then use non Freesat mode. All the free-to-air channels that the box can receive will then be listed.
You don't need the channel editor hack to receive non-Freesat channels. You do need it to edit the main channel list, but this isn't really advised because the box (and the software) will misbehave badly if you don't tread carefully.
Nothing you do will get encrypted channels on your Freesat receiver (unless you use some dubious means to make it work with a Sky card - but if you have one of those you might as well use a Sky STB).
Cheers,
David.