Digital BW, The Print

I am printing on an Epson 3800 using Epson inks. I have a print with
large areas of black that I have a couple of small (maybe the size of
a piece of glitter) areas of white. What do folks use to spot inkjet
prints? I assume you could get small reservoirs of the relevant ink
and spot using this? The areas I need to spot are in matte-black
areas. Any easy sources of ink are appreciated - a Google search
mentions draining "empty" carts and using this ink; using water to
draw ink from nearby areas of print into blank area; watercolors;
running sheet of transparency through printer and picking up non-dry
ink off the sheet of transparency film. Opinions, other ideas?

Thank you,
J