I seem to recall reading or hearing a very long time ago that where a
printer has not been fired up for eons that the pins can be stuck in the
print head (e.g. by old ink drying out) and cause damage (e.g. bend pins)
when it tries to print.
A word of warning. Unless you really know what you are doing, do not dismantle
a dot matrix printhead. Many of them were initially made with pins that were longer
than the finished ones, the head was assembled and the pins cut and ground to the
correct length. If you take it apart you will never get the pins back in the guides
correctly.
A few can be taken apart. One early Epson one (also used in the Commodore
2023, etc) will split into two parts, the pins in their guide and the solenoid assembly.
The latter can be stripped, but don't be tempted to unclip the back end of the
former!
The Teletype Model 43 printhed can be taken apart, the method is documented in the
service manual.
Sanders 12/7 and 700 printheads are quite easy to take apart (but keep the
pin/armature assemblies in order).
Other than those, I wouldn't strip any of them!
Maybe clean the face with propan-2-ol and then soak that end in the same solvent to
remove any residual ink..
-tony