Have been "saving lots of money" by injecting my printer's cartridges. It suddenly ceased to work in the middle of an important job no doubt for this very reason. In vain we tried all the usual tricks like dipping the print head in boiling water and attempting to empty the sump, (springs, bits of tube, foam rubber, and rainbow ink drops flying all over my office).
I had to rush out and buy a new printer.
Its very expensive cartridges GLOW IN THE DARK.
Why?