Back to Xline today. Gardiners brush is next to useless on snail trails. Which is a shame.
Snail trails need a circular motion to clean them properly with a brush, plus as the majority are on ground floor windows then if you do get a tough one a rub will a damp microfiber will sort it quickly, what I'm trying to say is they shouldn't be a reason to work all day with a heavy brush.
Not joking you wouldn't believe how many pole users are afraid to use any other tools but brushes, I watched a guy a while back scrubbing for dear life at bird poo on a ground floor window before he would pull out a scraper or even try his fingernail which would have removed it in seconds.