Who knows if people who have had surgery can sleep on an ochre mattress with titanium plates and steel nails in their bodies?
As far as I know, most of the orthopedic internal fixation materials are titanium alloy, not iron, and even if there is a magnet, it will not attract.
As for the ochre mattress, the formal medical literature has not mentioned its therapeutic effect so far. At most, it promotes blood circulation and accelerates metabolism by heating.