I think the liquid is cheaper than the dry and liquid dissolves so much better as well. The liquid for 5 or 10 gallons will only cost you about $2.50 and you'll have plenty of washing soda and borax left over to make more.

Here's my Homemade Laundry Soup Recipe:
4 cups hot tap water
**1 Fels Naptha Soap bar
1 cup Arm & Hammer Washing Soda
1/2 cup 20-Mule Team Borax

**you can use Ivory, Sunlight, Kirk's Hardwater Castile or Zote Bars instead. Don't use heavily perfumed soaps!

Grate bar of soap and add to saucepan with water. Stir continually over medium Heat until soap dissolves and is melted. Fill a 5 gallon bucket half full of hot tap water. Add melted soap, washing soda and Borax. Stir well until all powder is dissolved. Fill bucket to top with more hot water. Stir, cover and let sit overnight to thicken. Stir and fill a used clean laundry soap container half full with the soap and then fill the rest of the way with water. Shake before each use as the soap will gel.

Optional: You can add 10-15 drops of essential oil per 2 gallons once the soap has cooled.

Yields: 10 gallons liquid soap

Use 1/4 cup per load unless you have soft water. If you have soft water use just 1 Tablespoon per load.

This works very well and lasts a long time!
**I only make 5 gallons and use 1/4 cup per load because most of my laundry is pretty soiled (4 young kids)
------------ --------- --------- --------- --------- --------- -

Another
* Shave one bar of soap into the large Folgers or Maxwell House Coffee Can (plastic with lid) Add 1 cup of Borax, one cup of Sun bleach for colored cloths or clorox bleach for colored cloths.
* Add one cup of Arm and Hammer Super Washing Soda (from Publix, ask for help if you can't find it)
* Add one cup of baking soda.
* Stir it all up. Add two big tablespoons to a large load of laundry detergent.
------------ --------- ------

Use:

1 cup baking soda
1 cup borax
1 cup of your preferred laundry soap.(this write uses Tide for cold water, coupons this weekend!)
Heat in four cups of water: add water if needed as it is cooking.
When completely heated and the powder has turned into a cloudy liquid, turn off heat and go one to next step.
Dilute this cooled mixture with two gallons of water in a five-gallon bucket and let sit over night.
In the morning, this mixture may have a thick film of soapy goop on top. Chop it up and stir it in. This process occasionally requires a blender to get the largest chunks to blend smoothly into the rest of the mixture.
When it is completely blended to your satisfaction, (this does not have to be perfect but it is up to you), add your favorite dishwasher soap to the cooled mixture. Vigorously stir with a whisk to make sure the blending is complete.
Once complete, put into bottles of your choice. Large seltzers bottles or recycle those single-serving water bottles for this application but you can also use leftover recycled laundry soap or dish soap bottles as well. Tip: It is easier to pour from the single-serve water or soda bottles.

This recipe makes two gallons. You will not need more than that in two-three months depending on the size and frequency of your dishwasher loads. You can see why this recipe requires only 4 boxes or bottles of your favorite dishwasher soap per year.

If this recipe does not work in your household, you may have extremely hard water and you will need to cut back on your dilution. If you do not want to waste what you have already made, simply add another box or bottle of your favorite dishwasher soap to the mixture this time and when you make it again, simply do not add as much water to the recipe. (Cut back on the dilution with water by half to start)