Let's face it: dualstrusion with PLA really doesn't work very well. The ooze from the waiting nozzle is generally enough to destroy a print. However, there is another way!
If your objects are narrower than the space between your nozzles, you can alternate the STLs of the dual halves (better to look at the pictures here). Then using Ditto Printing in the Sailfish firmware, you can use both nozzles at once, doubling your throughput. This is how I managed to print 60 of these bearings on my Rep1 to give away during just two days of Makerfaire.
You can customize these bearings if you wish, though you can't make them much bigger unless your nozzles are further apart. The main point of the customization is to input the exact x- and y-offset of your nozzles. These must be accurate to within ~0.1mm, and you can use a test object or calibration script to measure this.
Keep in mind, you'll always end up with a half-object on each end, but I can still fit 5 completed ones onto my Rep1 build plate.
Obviously, this method can be used for much more than just these bearings. The idea is fairly simple, but you can always open my OpenSCAD code to see exactly how I'm doing it.