Paul, who is far more knowledgeable than I wrote:
"What I saw an authorized Epson repair person do was take a syringe of
water, with a tube connecting it to an Epson printer head that he'd removed
from the printer. He was able to squirt water straight through the head. I
don't know what impact this might have on the head itself."
I have conducted this procedure using Windex at various dilutions (with
distilled water) to get rid of "terminal" clogs. My sense of this, supported
by several recent experiences, is that some Epson heads tolerate this quite
well while others don't. I can speak from experience that the head on the
C84, for instance, has a design in which relatively little pressure on the
syringe is enough to displace the barrier between inks inside the head
allowing the colors to mix internally. This is usually a fatal event (for
the printer!). The last time I tried it I had ink from one chamber bubbling
up from the "nipple" on the next one. NOT good. The larger format printer
heads and the older heads seem to tolerate this better. The cheap desktops
like the C-series do not. If you do attempt to force ink, cleaning fluid or
distilled water through the head, please do so with extreme caution. If the
head flows freely this will be less of a problem. If it's clogged with no
outlet for the ink it's likely to be more of a problem. YMMV!
Rick