Actually both Ilord & Kentmere published data sheets & formulae for the Etch Bleach process in the 70's, 80's etc until quite recently in the case of Kentmere. It's a wash off relief process usually used in the graphics field. With an RC paper the remaining relief is dyed, sometimes selectively using dyes. Most definitely not an archaic process, but not need in these days of large format digital printer. I'd be surprised if Kodak didn't publish a data sheet on the process, but probably in the Graphic Arts field.
Etch Bleach also has some more creative uses, as if the bleach is used after development without fixing the remaining image can be re-exposed and re-developed.
The process will work to make silk screens by enlargement.