Just got some vivi and extra thick methyl and extra thick natrasol from messy supplies, follow the instructions or experiment a bit. I did a two part methyl, one part natrasol and one part vivi slime in a small batch and the result was interesting, thick, stuck to the skin a bit, but also stuck together(stringy).
Made a very small batch, 3 cups of water, and used teaspoon ratios to play around with combinations, but I liked the result, had to leave overnight to thicken, as with mixing all three they have slightly different mixing needs, but if you want thick, slimy, sticky, stringy slime without overnight prep, mix the natrasol and vivi as per the instructions (both are similar prep) and you should be good to go.