So, are the old ways always the best? I tend to think so, being a grandma. In this particular case, however, I'd recommend more modern methods, although the advice on removing all of the filth before you start is still relevant.
|Nicolas Arnoult, Recueil des modes de la cour de France (1687), LACMA|
"How to make ones haire to become of a yellow Golden Colour. Take the rinde, or outward parings of Rhubarbe, and put them to steep in Whitewine, or clear Lye; wet a spunge or linnen cloth therein, and anoint your haire therewith, and let them dry before the fire or sunne; the oftener you do this the sooner they will become yellow: note that before you use this, it is good to clear your head and hair from sweat, and all other filth whatsoever."
~ A Brief Collection of Many Rare Secrets, La Fountaine, Edward (1650) (text of the entire book is available here).