The writer lives in a hard-water area and recommends the Kärcher Window Vac WV 2 to get rid of streak marks on the shower screen.
Karcher KB 5 Lightweight Multi-Surface Cordless Electric Hard Floor Broom - Ideal for Fur, Hair, Dirt and Debris 1.258-009.0 - The Home Depot
Outstanding Performance: The WV 1 Plus's rechargeable, lithium-ion battery provides cordless freedom and features a battery run time of 25 minutes
Kärcher - WV 1 Plus - 2-in-1 Window Vacuum Squeegee - For Showers, Mirrors, Glass, & Countertops - 10 in. Squeegee Blade
CV 66/2 Kärcher
KARCHER WINDOW VACUUM REVIEW BEST WAY TO CLEAN WINDOWS WITH NO STREAKS
Karcher 16.9 oz. Streak-Free Window Cleaner Concentrate
Review: Karcher KV 4 Cordless Vibrating Wiper & WV 6 Plus Window Vac - Consumer NZ
Kärcher Window Vacs: the Mumsnet guide 2021
Karcher WV5 Plus Window Vacuum Cleaner
WV 6 Premium
Outstanding Performance: The WV 1 Plus's rechargeable, lithium-ion battery provides cordless freedom and features a battery run time of 25 minutes
Kärcher - WV 1 Plus - 2-in-1 Window Vacuum Squeegee - For Showers, Mirrors, Glass, & Countertops - 10 in. Squeegee Blade
WV 6 Premium
This Karcher Window Vaccum Is Ideal for Hard Water Areas
Window Cleaner Concentrate for Window Vacs
Best Karcher Window Vac Models for Spotless Cleaning — Eightify