I was cleaning the inside of the windscreen not the outside. I’ve used rain dispersant on the external screen with mixed results. The best one I found was Supagard. .Since we had a new windscreen in our car paid for new wipers and rain repel, which is a coating for the windscreen any rain water it seems to run rapidly away .
The problem with some dispersant is the refraction and reflection with low sun. I still fine Fast Glass and Crystal Blue applied and buffed up with kitchen roll,or similar.I was cleaning the inside of the windscreen not the outside. I’ve used rain dispersant on the external screen with mixed results. The best one I found was Supagard. .
Internal or external windscreen? No issue cleaning external, but that fine "mist" on internal windscreen is a pain.For most car cleaning now I use Bilt Hamber products, for glass specifically they've recently brought out "Traceless". I guess this follows on from their Touch-less snow foam and Touch-On wash and 'wax'.
It's isopropanol-based so should evaporate and be traceless! For the caravan windows I still use Auto Glym fast glass.
For rain repellent coatings, Bilt Hamber Touch-On is sufficient for the side windows along with the paintwork, but I use Gyeon Q2 Quick View for the windscreen. Excellent performance at motorway speeds and very easy to apply every couple of months.
Like you it’s my inside screen that I was most concerned about and so far I’m pleased with the results from the E-cloths, but must admit I should do it more often which might help.Internal or external windscreen? No issue cleaning external, but that fine "mist" on internal windscreen is a pain.