I have one of the Giovanni 3 in 1 bath products and I love it! I use it for a shower gel and my BF washes his hair with it.
I sometimes use Shea Moisture Deep Cleansing Shampoo to wash my face with.
I now use HEHH to shave since I stopped using it on my hair.
The Darcy's Madagascar Vanilla Styling Creme became a damn good body butter when I retired from using on my hair after winter.
You still have to watch the ingredients and there are things I will never wash my hair with, etc, but for the most part, many products are interchangeable.