I use pea gravel & a rake. I spray, rake, spray, rake, spray... well, you get the point.
I have three Anconas & since I added the pea gravel to my wire mesh floor I have had a much easier time keeping their enclosure clean. I have pea gravel over the wire, and in winter I throw a layer of hay over the pea gravel.
I have never had problems with them eating the pea gravel. They nibbled it the first day & spit it out. I think it is too big to be grit & not tasty enough to be food.
My enclosure is raised a bit (maybe 2") off the ground, so when I rake & rinse it doesn't pool under the enclosure, which would probably make it harder to keep the gravel clean.
I have a friend who uses some gunk for cleaning her aquarium rocks (an enzyme) in a sprayer two or three times a year in her duck pen, but it is not raised at all. I am not sure of the name, but I'll try to shoot her an email & get back to you.
Good luck.