Lol, yeah you can't save in there.
Ok, to RNG in the Safari Zone. Here are the basics:
Save in front of the man that lets you inside. Hit your seed. Once you verify your seed, talk to the man to get inside. Then get into a grass patch (I usually save with a repel activated) and find out what frame you're on by calling Elm (Since stepping in the grass advances by 1 or 2). Then advance to your target frame and use Sweet Scent like you normally would! :D
But you won't know what Pokemon you'll get unless I teach you the slots. Unfortunately, it's really late here and I don't feel like teaching you (Sorry D:) so is it ok if I teach you tomorrow? For now you can just try your luck and see what you get, and tomorrow I can teach you! I hope that's ok.