One thing I like to do when working with plastic models is, once the model is cleaned up I often a apply a coat of liquid poly (plastic cement) or sometimes just airbrush cleaner to melt and smooth the marks left by craft knives and to melt away some of the plastic waste than is still attached to the model.
I've tried a few products on the PP plastics but they refuse to melt. As per the guide for the Bastions in NQ, I use superglue to attach the models together.
Anyone any ideas? Don't fancy an ultrasonic cleaner or excess time spent on clean up!