Rodinal-like developer from Metol
Mix 40 grams of Metol with 15 grams of sodium sulfite in 1 liter of water. Add 19 grams of sodium hydroxide. Filter, saving the contents of the filter paper. That which passes through the filter is mostly sodium sulfite and sodium sulfate. That which remains is mostly the Metol base. Mix the contents of the filter paper with 750 ml of water and add 85 grams of sodium sulfite. Stir vigorously while adding 19 grams of sodium hydroxide. All or nearly all of the precipitate will dissolve. Bring the volume up to 1 liter. Use as you would Rodinal.
The result is a solution of a sodium salt of the Metol base and sodium sulfite.
I also made a batch in which I mixed the 85 grams of sulfite, 40 grams of Metol and 38 grams of hydroxide to make a liter which included the sulfate formed from the H2SO4 of the Metol. It is a little darker in color, but I haven't seen a difference in performance. Sodium sulfate is sometimes used in tropical developers to slow the reaction and minimize swelling of the emulsion, but the amount created here is probably not enough to do that job.