I guess clean is all relative. The one guideline I'll follow no matter what is protein with every meal. I do have some junk every once in awhile, though for some reason fast food hasn't appealed to me for a few years now, but I will have a bowl of icecream or something similar...also, I have been known to have a few beers on occasion as well. I'm super strict when I'm dieting down, so I'll take the time to eat some crap while I'm bulking, but I don't go nuts, and I don't gain all that much fat.
I'm currently in the beginning of a bulking stage, this time I'm really shooting for a big gain, I'm going to see if I can pull off 30 lbs over the course of 6 months, and this will require some big calories on a daily basis because I don't gain weight easily, and if I should slack on a bulking diet for even a week I can lose five lbs fast. But yeah, I do enjoy the things that I won't get when I'm dieting though I take them in moderation.