Welcome to HCM
We understan your concerns
Multani mitti contains several minrals, metals and compounds and even micro organisms. Most of these metals and compounds are dangerous if taken inside like copper and lead.
You are inclined to eat multani mitti because your body is deficient in some of the minerals vailable in that. You have to find out which one and take oral supplement for that mineral. You are not adicted to multani mitti as a whole but to some of the minerals it provides.
Consult a dotor an get all the tests done. Find out which one is deficient and as per his advice take oral supplements.
and headache could be associated with this habit.
Get well soon.