It's important to use a NYLON brush - NOT a steel brush - when scrubbing out things that you don't want to scratch. Obviously, glass tubes (as might be on the front of a coffee urn, so that it's easy to see the level), should not be scratched.
Any glass or plastic tube should be cleaned with nylon. In addition, things like the internal surface of the frothing wand on an espresso machine WILL get worn with repeated scrubbing using the (standard) steel brush. You could use the nylon brush for routine cleaning, and the steel brush weekly. This will give you more wear.
This brush is a fairly flexible wire brush with Nylon bristles. It's very useful for getting into the corners of your grinder base, and into the dosing chamber, as well as up into the group of your espresso machine.
It's important to brush those particles out when doing daily cleaning, because if they become rancid, they'll impart an off-tone to freshly ground coffee.
This brush is 1/4" in diameter, so it's about the same diameter as your 7 millimeter frothing-wand brush. So the nylon brush will do (almost) the same job as your Pallo brush, but with slightly less damage. You should use the nylon brush often, and the Pallo brush occasionally.
The standard soft grinder brush has soft bristles, and it won't dislodge deposits stuck in the corners of your coffee grinder. This brush has stiff bristles, and will dislodge those deposits. Brush is 1-foot long, with nylon bristles being 1/2" in diameter. A very useful tool for your coffee station to clean your coffee grinders and your espresso machine.
And an essential brush for cleaning glass or plastic tubes.