How to make Magnesium Oil spray

As I'm writing this, I'm spraying my magnesium oil spray on my knees, my biceps, back of my neck, back of my thigh, basically everywhere, because after a long walk this morning, I am feeling the burn on my joints and muscles; I need something to soothe them before I do my yoga. 
It tingles, but the effect disappears after about 10 minutes.  When it has no effect, I probably have enough magnesium there.
The basic ingredients for magnesium oil are:
1 part water (room temperature)
1 part magnesium flakes (magnesium chloride)
mix them together into a spray bottle.
Then you add whatever essential oils you prefer to the mixure.
1% - 1.5% out of the entire mixture's weight is the guide.  
Around about 20 - 30 drops in 100g.  Depending on what kind of essential oils you are using, as some drops are "heavier" than others.
As an example, when I use Cassia to give heat, I'd use very few drops into my mixture as too much will probably dry my skin out.
The rule with essential oils is always to test it first on yourself if you're allergic to it.
  
I don't like measuring essential oils in drops because they're all of different densities and if I was making lotions, I would never ever measure in drops.  
However, in this case, I probably will only be working with a small mixture in order to finish it quickly and therefore not needing perservatives, it's probably easier to use drops.  
Why make things complicated?
Happy experimenting!