Yep.....that said, I was able to get sodium hydroxide from the hardware store as drain cleaner (highly caustic, use gloves, need to read lable to get right stuff). If you do use NaOH, make sure you add it slowly to the developer stirring. It heats up as it dissolves. Anyway, you'll need ph strips or a ph meter (I have a cheap one for aquariums). I'd just get the real lith developer. Life is short. Also, diluting regular developer isn't the same as diluting lith developer. You'd need to experiment with the dilution. Sounds like an interesting experiment.