I used slow cooker when I first started baby on solids. https://shp.ee/jxg7q3d When she first started, a few teaspoon then gradually increase. I cooked 1-2 tablespoons of rice (usually will have leftovers so I will eat together). I use japonica rice, after cooking, I will use the masher feeding bowl to further mash the porridge as I don’t blend the grains before cooking (no blender). https://shp.ee/ru7jbh7 After 1yo I used rice cooker.
normal rice cooker. introduced porridge at 7 months and puree at 6 months. cooked 1/4 cup rice until very mushy (there's a porridge setting on the cooker) using normal rice cooker and slowly increase if baby can eat more.
Can google and check out 十倍粥