Does carbon dyeing hair really help? Can you dye grey hair with it so laser may remove it?

ive got mostly grey hair on face that are related to acne, sebum plugs , etc.have started taking isotretinoin recently. after it's done (& also a gap of 8~9 months) I'm planning to go for hair removal, but although these hair are grey they've got nearly melanin-less follicle. they look really terrible for me. if carbon dyeing isn't going to work then shall I shave them so they might grow darker or within a laserable color range?(I'm currently 18y old)