I'll explain. When basing (which I dislike), one of the things which annoys me most is the fiddly processes of
(1) applying glue around the feet;
(2) dipping the model in the gravel etc. and trying to ensure an even coverage;
(3) waiting (overnight) for it to dry;
(4) basecoating it all black, which is fiddly;
(5) drybrushing it grey;
(6) edging the base in black, and
(7) applying the identification flash.
Now obviously, had I not already undercoated all of my models, I could apply the gravel and then spray it black. But 'tis too late, as always.
A while ago, I tried emptying the contents of some ink cartidges into the tub. This worked, but not too well. The coverage of the gravel was uneven and rather watery.
BUT TODAY...I got into the bright lights of the local town and bought a pot of Indian Ink from a stationer's shop. Genius! It works so well that it'll negate the whole fiddlyness of step (4)! Hooray!
That only leaves steps (1, 2, 3, 5, 6 and 7)!
Incidentally, the gravel I use is a mix of GW's and some other stuff.