Slip Plate sprayer and valve cloging

[Electronic M]

Was shaking it decently. It ran out of propellant last night so I did an autopsy...The valve was making crunching sounds in operation. After making sure there was no pressure in the can I punctured it and decanted the remaining paint into a twist off glass soda bottle (for future use) and cut the can wide open...The 'mixing balls' were a pair of the most chipped up glass marbles I've ever seen....

My theory is that after a few uses (read times shaking it) the marbles made enough glass chips that every time I unclogged the sprayer new ones would be rapidly sucked up and re-clog it...