Well, for those of you interested in mixing your own Rodinal, I would like to add some caveats on the NaOH or KOH solution used.

Making a 50% NaOH solution involves 50 g of NaOH diluted to 100 ml for a wt / vol solution or 500 g diluted to 1000 ml for a larger quantity. You must start with ICE COLD distilled water, about 25 - 30 ml or 250 - 300 ml depending on volume. The slow addition of NaOH solid is so exothermic, it can crack some glass containers and can actually melt some plastic containers. You should have a large container of cold water to chill your mixing vessel.

After you are done, there is much residual heat and you should cool the mix in a large mixing vessel. Make sure that no excess water gets into your diluted 50% solution.

Leave the cap loose as it cools or the reduced pressure due to air cooling or volume reduction may crack the storage container. Glass can shatter, plastic can melt or crack. Do not store the final solution in glass, as NaOH can etch glass and can dissolve some inexpensive glasses. A spill will ruin most floors even concrete.

Wear a lab coat with sleeves, old shoes, dirty clothes and protective glasses along with rubber gloves.

That is how I just did it, and what I experienced and I am an old hand in the lab. Be careful, don't disfigure yourself or blind yourself from a tiny splash and don't ruin your darkroom from a spill.

Have some automobile battery acid on-hand in case of a spill. I bought a gallon of 37% battery acid to have here just in case before I did this.

Be happy, be safe, mix Rodinal by any formula with care. Mixing the NaOH or KOH is the first dangerous step. Adding this to the pAP and Bisulfite is no snap either. Take care when you do it. It is an acid base neutralization.

PE