Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
we stopped using those damn things years ago, they're terrible. use a regular kitchen sponge. color coded per chemical, ink & haze. they're cheap and can bend around corners and frames easily... they last a few weeks too.
I got a sample of some chemical resistant styrofoam a few years back. I still us the sample. It is awesome and never breaks down...
We liked the way a typical auto was brush worked, neve lost a bristle relatively cheap from wallyworld.