@AliOop i just came on to look up ingredients and ratios for laundry soap - I made a big batch of 0% SF coconut soap for dishes /stain stick several months ago, and no-one wants me to share with them! NO-ONE!! I get that washing with a bar, and rinsing a lot, is different than squeezing Dawn into the sink of water. And maybe our hard water makes solid dishwashing bars trickier…(I did add citric acid, but that only goes so far)I personally wouldn't use anything but 100% CO or PKO with 0% SF for making the "soap" part of my laundry soap. Those have the highest cleansing value, and they rinse cleaner than other oils that have higher conditioning values.
Think about it... you don't want to "condition" your clothes with anything, not the FAs from the oils you use to create the soap, and not from SF, either. So while you can absolutely make laundry soap from other oils, and it will work, I don't believe it is the best choice.
One thing to keep in mind is that homemade laundry soap works best in hot water. To wash in cold, it's best to pre-dissolve the powder in hot water, and then add that mix to your load. Even then, you will get more scum in your washer, and will need to clean it more often.
Finally, if you will be using very hard water to wash your clothes, homemade laundry soap is probably not the best option for you. You will have lots of soap scum from all those minerals, and your clothes will probably get dingy because they won't rinse clean. Sorry
EDIT: my laundry soap recipe is actually a mix of 1 part grated CO soap, 1 part borax, and 2 parts washing soda. What I was trying to say above is that I only use CO or PKO to make the "soap" part of the mix.
Anyway, I thought I’d turn some of the bars into laundry detergent, and I just finished a grating session…only to read your post about dingy clothing and scummy washing machines. Any suggestions for what to do with 200 grams of finely grated soap?
(maybe one day I will learn to research first, then act. But I doubt it.)