I have had this recipe for a long while and am not sure where it first came from. It works fairly well. Taking advantage of sales on conditioner can increase your savings. I usually double and sometimes triple the recipe, but you can halve it to make less.
4 cups of hair conditioner (32 oz)
6 cups of distilled white vinegar
12 cups water
2 gallon empty container
Heat the 6 cups of water on the stove in a pot to the point of just boiling. Add the condition and stir until mixed well. Pour into a large container or bucket, add vinegar, and stir well. Pour into recycled bottles. Shake before use. Label clearly.
One good thing I have discovered with this is that it doesn't "gunk up" the fabric softener compartment on my washer like the commercial product did.
When I have not had time to remake this, I have used distilled white vinegar by itself, and it works well. The vinegar smell washes away.