I read that Eucalyptus Oil was good for asthma and other breathing problems. This grocer across the street at Abarrotes Mi Familia carries a few OTC products that are widely used in Mexico, including the Eucalyptus oil. It is a real bargain at $3.49 for a 2oz bottle. Tried some of it out, in a pot of steaming water and in my bath. It does work. I dunno about the purity or other technical details.
They have sweet almond oil, coconut oil, and a few other oils (but no tea tree or lavender oil).
The Mexicans seem to like Sulfa. Many of their products are Sulfa based. I like their Vitacilina, which is a NeoMycin ointment. Works good. It is not as good as the V.A. Medical center’s prescription antibiotic though. I have big respect for Mexican Medicos after my visit to Los Algodones.