I have used a mixture of phenidone, hydroquinone and sulfite which does pretty much what D-23 does but better. Try:
0.1 g phenidone
at least 8 g hydroquinone
100 g sodium sulfite
water to 1 liter.
The phenidone will activate only a certain amount of hydroquinone. Adding more than that amount of hydroquinone has little effect on activity but increases capacity and resistance to aerial oxidation. I have used this concoction as the first bath of a 2 bath just as I would have used D-23. I could not see any appreciable difference in the H&D curves, but you may. As a single bath developer, the capacity is 8 or more rolls or 8X10 sheets/ liter without replenishment.