To 400 ml water, add:
85 g anhydrous sodium sulfite.
40 g p-aminophenol base.
Stir well. Add
13.8 g sodium hydroxide or 19.2 g potassium hydroxide.
Add water to make 500 ml.
No matter how you stir, there will be some precipitate of p-aminophenol. Don't filter it out. The theory is that as p-amonophenolate is oxidized by air, the hydroxide is formed which combines with some of the precipitate to form more phenolate.
With the chemicals we can buy from Photographer's Formulary and other current sources, there is no need for the titration to leave "just a few" crystals undesolved. All the weighing and mixing can be done in a few minutes. Using the p-aminophenol base instead of the hydrochloride, and the sulfite instead of the bisulfite cuts down the amount of hydroxide needed. The net result is the same except for lack of an amount of a chloride. If you think it is necessary, you can add an amount of canning salt (non-iodized) equal to about 1/2 the weight of p-aminophenol. I can tell you it never will be missed if you leave it out.
PF can sell potassium hydroxide without the special forms etc.