BetterYou Magnesium Sleep Bath Flakes – Relax and Unwind. Relax and prepare for a restful night with BetterYou Magnesium Sleep Bath Flakes. Made with pure Zechstein magnesium chloride and calming lavender and chamomile, these flakes help soothe muscles and promote sleep. Add 250g to your bath or 150g to a footbath, and soak for 20 minutes. Unwind naturally with BetterYou Magnesium Sleep Bath Flakes.