Most of the recipes going around for laundry soap, liquid or flaked/granular, call for appallingly large proportions of alkali such as washing soda and borax. At the time soap powder was state of the art for laundry detergents, these would've been considered cheap, low quality formulas that would tend to degrade fabrics unnecessarily. Nothing wrong with adding a little alkali to laundry detergent, just that it shouldn't make up most of the mixture. Laundry soap should be mostly just that: soap.
If you want to make liquid laundry detergent based on soap, you're going to have to avoid large quantities of sodium, which will tend to jel the liquid, resulting in that "gloop". One expedient would be to make potassium soap (into which you can mix a little sodium soap if you want to thicken it -- although I don't see what the objection would be to having it runny -- or to saponify with a mixture of KOH & NaOH to do the same thing) and just add a "builder" such as washing soda to the wash water separately. Otherwise you're going to have to use non-sodium builders that'd be harder for you to find in hobby quantities, such as tetrapotassium pyrophosphate, which was used in Wisk before phosphate restrictions.
One little catch: If you're using a HE machine, I'd recommend against using soap in it for any reason other than as a minor additive for reducing the foam of other surfactants. You can make a low sudsing soap mixture that's a somewhat effective detergent, but only by overloading it with those alkali that are in those formulas I've criticized. Then you're relying on the brute force of alkali to do the cleaning, with a little soap as wetting agent, which I wouldn't recommend for washing cotton, rayon, polyester, nylon, silk, hemp...gee, about the only fabric I can think of that wouldn't suffer is acrylic. If you want to clean with something that actually uses soap to do the cleaning, I'm afraid it'd lather up a HE machine to a degree that would tend to float the articles being washed.