That switch looks identical to the Ford! Ya, pretty much all of my cars have switches that look like that.
If you're legitimately worried about solid stuff contaminating the lines, I would blow out each one individually and have somebody at the end to observe if anything and what comes out. Maybe blow into a bucket or something. Disconnecting them all from junction blocks will avoid any "cross-contamination" and the order they're cleaned won't matter.
Did the guy have tape or rubber plugs on the ends of any of the lines?
I'd be more worried about internal rust than anything else. If any solid particles that look like rust come out, buy new pre-bent lines.
