In my childhood, I had tried growing musturd in the bowl having cotton as growing medium. It grown much well. Also tried Money plant & water-cabbage in water. Regular soil is used for potted plants. So my question is; Is there any other growing medium for any indoor plants, that is more suitable than soil?
There are commercially granules that retain water turning into gel: these may be used for the hydroponic cultivar, mixed with little shells, little pebbles and so on. You need to control the light and to put hydroponic fertilizer.
You can color the gel with alimentary colors, for a nice effect into glas pottes. image http://www.lugano-ticino.com/scienza/polimeri/images/idrocoltura-polimeri-espansi.jpg
Rock wool can come in blocks and is used for hydroponics and also that stuff that florests use.. Oasis? but you'll have to provide nutrients for the plants once they get beyond seedling size as the medium they are in is only for support of the plants structure only and won't feed it in any way- rock wool is also sterilised against fungal infections etc and can be used several times.