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. 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 5/8" in diameter, so it is much larger than the normal steam wand brush that you already should be using with your espresso machine - although we recommend getting the quarter-inch nylon brush for use with this too. This will give your frothing wand AND your Pallo brush longer wear.
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 5/8" 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.