[Pro-Poler]

Got a sill brush and it's only about a month old and the bristles on one side have squashed, tried hot water and that didn't straighten them?

[PoleKing]

Me too.
Try boiling hit straight from the kettle.
Then, take it out if the bucket and run under freezing cold water with the water flow pushing the bristles where you want them-if you know what I mean.
It gives an extra few weeks.
I'm on my 2nd cill brush in 7 months.
But by normal brushes look almost new for not that much less work...