That red stiff brush is to stiff imo it’s like using a bass broom over the glass,I like a brush to have a slight flop on the window but not to soft that it collapses.
So many brushes out there that work fine with water that’s reading 4-5 degrees,once the water starts getting up to 60-70 degrees it finds em out,they collapse and deform in days it’s easy to just stick something in a stock that resembles wire and say that’s for hot water. I had another go with that red bass broom yesterday my water was 65 degrees and it hardly splayed lol,that’s not a good brush.