Here is a quick formula 1kg fresh or 200g dried stinging nettle cut to pieces, add 10l cold water I use a 5gallon Bucket and just filled it up with the plant material and added water to 4/5 since there could be some foam coming up.
this will have to stand with open lid where sun (best)/light can reach it for 1 1/2 - 3 weeks depending on weather condition, you just have to stirr it day by day at least once to increase oxygen amount in the liquid.
After 3 days it is good to use as a spray against any bugs or bad bacteria (to water the soil against root deceases 2) because the 'sting' just left the nettle but still remains in the water, if you try this 1-3 days later it will mostly already be to late to use it in this way because the 'sting' is gone...
...and then the mycrobes go for converting it in a pretty bad ass smelly in the beginning green later on till brown manure/brew that kicks ass for 0$ and if one day you search for a way to hide the weed smell pour a little of this one, nobody will ever again complain about any weed smell anymore -trust me
adding a hand or two full of dolomitic lime would be recommended you can even blend some guano in - i added it seperately but dissolved in water 2
you can if you got the right herbs growin somewhere near you, blend it with comfrey and/or common horsetail which will improve it as a fertilizer. I am going to work on the recipe until i think there is nothing better to use since i found the only nettle based already hella potent -and dont forget the mykorrhiza to eat all that stuff up
EDIT: WARNING! Do not touch brew with bare skin, the odor will stick to you real hard. Using this is the Pai-Mei or if you like better Major Pain way to learn how to proper hand water without spilling any.