Brother GTX600NB Instruction Manual page 192

Ink clot example
<CAUTION>

When removing ink clots, do not use hard objects like iron tweezers. The nozzle may be damaged, resulting in non-ejection
if the objects touch the nozzle or other parts.
Use gloves and remove ink clots by pinching them with a clean stick or your fingers.
(11) Clean the top of the steel plate next to the flushing foam.
Precautions to keep good printing quality/use printer over the long term
Cleaning location
6-24