I sleep with my henna on I just wrap my hair in saran wrap and top tht with a plastic cap and top that with a scarf. I sleep with it overnight and then wash and D/C sometime the next day. I haven't done a treatment in a minute but I will be doing one tommorow I have my mix setting as we speak. I used henna/cloves/paprika/cayanne pepper/lemon juice/water, tommorow after the color releases I will add alma oil and conditioner and sense I am breastfeeding I have some fenugreek so maybe i'll throw some of that in as well.
Shadylane I slept in my henna and my urine was black for a couple of hours, it went back to its normal color but I was surprised to see black urine. I'm saying this to say, I don't think you should breast feed on that day after your henna application.. Just my thoughts on the matter.