Detergent is really personal preference and what works well with your water. I've used a lot of different detergents but have found Charlies Soap to work the best for us and our very hard water. I choose not to add any softener to the water to cut down on cost. CS is only I think 11 cents a load and for diapers and my DHs very greasy work clothes I soak on the hot wash for 30 minutes or until I remember to restart the washer

I have found that that gets even synthetics really clean. We have a top loader so that may help I know people who have great luck with there front loaders bit ours didnt do a good job at all.

So we sold it and bought a top loader and have had great luck. You order charlies online and if you order more than 28$ worth its free shipping so I just make sure to order at least 2 bags at a time. Each bag does 80 loads. Good luck on your quest for the perfect detergent.

Also staining depends on a lot of things one being how ling between washes and if you do a cold wash first (you dont have to use soap on this wash) I dont know if it is safe for hemp someone else will have to chime in but you can fill the washer or sink with straight hot water (after dipes have been washed) and soak all night then was as usual in the am. Works great! As does sunning.