I have a lifetime supply of VDH VanDer Hagen shaving soap in that little green box. I have always liked it for the way it worked, and bought a "case" of 12 on Amazon a while back since I could not find it again (replaced with different VDH) at my local Walmart. Then my daughter bought me a case of 12 of it for Christmas. It lasts a very long time. If it's like cheese it should be well aged now sitting in the box under my side of the bed.
Years ago in Nebraska I used to make lye soap at home from Lye (sodium Hydroxide) and beef tallow at the local grocery store. Worked fine, and there are a multitude of changes, as the type of oils or fats that can be used in this process. They even sell "homemade" lye soap here at a local "general" merchandise store about 3 miles from me.
I've also used DOVE bath soap that does a remarkable job with a good badger brush for a luxuriant lather on your face for shaving.
Back on the hard water issue... a water softener changes a calcium ion for a sodium ion as water passes by the beads. The beads hold so much calcium until they can hold no more and then the bead need to be refreshed... salt. Sodium Chloride flushes off the calcium ion and replaces it with the sodium ion and the water softener is once again capable of "softening" water. You get more sodium in your drinking water (not salt) depending on the degree of the hardness of your water. When you use soap in washing clothes there is affinity with the already "sodium" in the water and the sodium tallowate from the process of making soap (sodium hydroxide) works better. It is that slick feeling that you have when you wash your hands with soap and softened water, as it is the sodium ion ever present.
My suggestion is to get distilled water (it's cheap) and put it in a soap scuttle and microwave it for about 70-80 seconds. Makes it very hot. Then dip your brush in the scuttle water - soak - and then shake out a bit of water and work with your soap. It will lather like crazy. Alternate is to put in a water softener for you clothes and your pipes as it will save a plumbing bill later on if they clog up due to very hard water. You'll use less soap for clothe washing and dish washing and you have a ready supply of softened water for your shaving. If you use soft water for making coffee your coffee maker will probably never need the "vinegar" treatment ever again, as that is what we use for our coffee makers. I bring home the Winery's softened water for our coffee making and to cook with. It does not leave a ring around the pot or make it harder to clean like it does if I use our tap water.