First off, don't clean it in your darkroom. Take it outside or to your garage, anywhere but in the darkroom. I have used house hold glass cleaners, the mild ones, Windex, Sparkle etc. on the condensors and glass plates in the negative carrier. For the lens I would use a regular lens cleaner and lens cleaning cloths Dry everything completly and use a cloth that doesn't have any lint in it. For the body and bellows of the enlarger I would use a lighty, very lightly, damp cloth and some compressed air. Use the compressed air at a distance from the bellows, inside and out, and don't blow the bellows apart with to much pressure. Blow the surfaces off first, and then use the lightly damp cloth. A soft bristle brush, one that doesn't lose a lot of bristles, will also help.(posted 9519 days ago)Once you detail the enlarger, the darkroom comes next. Don't clean your darkroom to often. I know this sounds stupid, but the less dust you raise in the darkroom, the cleaner your negatives and prints will be. A little dust on things, that is not disturbed, isn't going to leap on to your negatives. I give my darkroom a complete detail once a year or so and touch it up in between, just the easily visible and reachable areas.