It's not really an issue. It sprays from an angle below that should minimize sprayback (no idea whether that is a word), plus you just clean it when doing the normal toilet cleaning. For sure is better than those overfull American toilets that welcome your butt with splash toilet water everytime you drop something.

The $300 add-on unit I have does self-cleaning after every use. When the sprayer retracts, it again sprays, but since there is now plastic directly above it, it cleans off the sprayer head on the rebound.