I finally bought round sponges!! Wasn't easy to find, but the ones with wooden handle are really comfortable.

After messing up with inks almost all the working table I used Fil's tips and scanned the textures I like most (with 600 dpi)  After turning them into bitmap files I've added them to the illustration of Parvati (Hindu goddess) painted as a wall poster commission while ago.

With adding the grungy inky texture the illustration became more alive and eye-catching.

Working process:

Using toned paper sometimes gives good results:)

There was no proper brush around so I've used pipette to pour inks to sponges.

One more neat thing about sponges - you can swirl your hand holding a wooden handle to get this awesome effect. It's like a fingerprints but without dirty hands:) was great to find that out during experimenting.

And here is the full illustration

Thanks! Glad to finally have a reason to buy sponges))