Yes, it is but you will have to search for recipes and ingredients. A good start is to search for "Chickens in the Road" and look for the blog on Liquid Soap. That will give you guidelines on how to make a liquid soap. Then research what oils are good in shampoos. Look at lye calculators to develop recipies. Good luck!
Another good source for detergent recipes is Swifty Crafty Monkey, another blogger.
Actually, this forum has many threads on making liquid soap. Including tutorials. I would not suggest the CITR to anyone. Those methods are outdated and unnecessary. However, I am going to warn you that there is going to be a whole discussion on whether soap should be used for hair. I can't use it. It just is a bad idea for my hair. Others have different results. And as for oil choices, that is going to be as individual as you are. You can search "liquid shampoo" and get most of the discussions on both liquid and bar soap, AKA shampoos.
Do you mean making a liquid soap from scratch using KOH? Or using already made "castille" soap, grating it, and adding it to water?
If you mean the later, don't bother, it makes snot. Many many people have experimented that one to death with no successes, I don't care what the blogs say.
If you mean the former (liquid soap from scratch), go dig in the liquid soap forum here. Susie and Irish Lass have put together some spectacular tutorials.
Now, whether either is good for your hair, try it and see, but be prepared to be disappointed. That said, I like to wash my hair with salt bars and a vinegar rinse once or twice a month, so go with what works for you.