Laundry Detergent - Final Recipe

I just made another batch of Laundry detergent, and I think I've finalized the recipe that works for me.  I use a dry detergent because it dissolves in the detergent slot in my front loader, unlike the liquid(ish) detergent that I made on my first try.  I've been using variants of this dry recipe for the last 18 months exclusively, and I have yet to have any difficulty with my HE LG front-loading washer.  This recipe is not scented, and I prefer it that way; now that I have used it for a while, Tide and Cheer (my old preferred brands) smell overwhelming to me.

For my recipe I use:

1 bar Ivory Soap, grated fine*
4.5 cups Borax
3 cups Arm & Hammer washing soda
1 cup baking soda

I mix it all together, making sure to break up any major lumps in the ingredients (Borax is especially prone to this).
I use one tablespoon per load of laundry.  If the laundry is especially dirty, I will put an additional 1/4 to 1/2 teaspoon of detergent in the pre-wash slot of my machine.

*I use a Zyliss Hard Cheese Grater to grate the soap.  This is the best hard cheese grater ever and I've had the same one for more than 10 years.  I've had the best success grating the soap if I take it out of any plastic wrap for a couple of weeks before I use it so that it has time to dry out.

This detergent has handled everything I have thrown at it in the way of farm clothing (dust, dirt, sweat, occasional blood and/or feces - farming is hard on the clothes).  I am quite looking forward to giving it the ultimate test - diapers for two babies.

This time I had leftovers from the last time I made detergent (in December, I believe) and so it didn't cost me a penny out of pocket.  However, in my last cost analysis, I erred on cost per load because I estimated that 1/8 cup (2 tbs) would be needed per load.  Since only 1 tbs per load is needed, detergent is now running me 4 cents a load - not too bad!