As for reticulation :(posted 8278 days ago)I have tried to do it on purpose with Tmax, it is impossible. I boiled the film (water at almost boiling point) and direclty transferred it in ice cold water, and the other way round too, but nothing happened. There might be a possibility that it will work with another film, though. I would try it with Tri-X and Fomapan or Fortepan.
As for the development: There are certainly many ways to augment the size of your film's grain by development but I don't think that you will ever reach a point such as you describe (large grain at 10x15 cm enlargment)... Maybe with old films like Kodak Recording, but not with modern ones. I would suggest a grain effect mask (you can still find some on the market) that you sandwich with your negs when printing them. Lith printing sometimes gives a grain effect (not always, though) but it looks different than what I think you expect having as a result. It also gives strange tonalities that you might not want.
There is a much more controllable and easy way to get the effect you want: scan your pictures, open Photoshop, go to Filter-Texture-Grain and there you can create any kind of grain you want, controlling the size, shape and contrast of your grain. I understand it is not really a photographic and romantic way of getting what you haze asked for, but it is surely the most effective one... You will just need a lab with a digital photographic printer to get the final pictures on photo paper. There are (at least in my country) labs that use B&W paper in the Durst Lambda printer and so you will even get a real B&W print, not a monochrome print on colour paper.