Is it okay to use epsom foot salts and takemagnesiumoxide tablets at the same time?

I assume...: You're talking about soaking your foot in epsom salt, not ingesting it. That being the case, knock yourself out. None of those "salts" are going to get absorbed into your body from the soaks, although you can save your money and just use warm water, which is just as effective. Also, hotter is not better. Plain warm water (2 parts hydrogen 1 part oxygen) is fine.