How long does it take to become ambidextrous?

It hurts when I brush my teeth.  My SUPER SPINATUS (Rotator Cuff) has betrayed me.  I'm not brushing my teeth particularly violently or anything.  I think it's just those wee little movements at that particular angle.  I start the day off wincing.  And what's really depressing is that it's not from having had twisty-bouncy sex the night before. 'Cause that kind of wincing is always accompanied by that satisfied smirk on your face.  You forgive the pain, because what went on before, was so freaking great.

I've decided that I need to stop using my right arm and become proficient with my left.  How long do you figure it will take?  Instinctively I high five people or reach for things or lean on that arm, so I need to abandon it, strap it down and begin using the other one.  I tried brushing my teeth with my left hand this morning and it didn't go well.  Water and toothpaste everywhere.  My spaz factor was at 11.  I wounded my gums.

I've got some great ambidextrous inspirations: Michelangelo, Einstein, Tesla, Leonardo da Vinci.  Very arty and sciency dudes.  And I'm not 100% sure, but if Escher wanted to his ability kept secret, he shouldn't have given us things like this:

M.C. Escher 1948

Plus?  I'm pretty sure that I could become a superhero if I were ambidextrous.  Less than 1% of the population is ambidextrous - which if we had accurate statistics on superheroes would probably reflect EXACTLY the same percentage!!  Or is that super models?  Me becoming a super model would take a bit more time and money I'm thinking.  The recuperation time alone from adding extra 3 inches to my torso and legs would be at least a couple of months.   Probably not as much fun as being a super hero either.  But step one is definitely the ambidextrous thing, regardless.  Which, seeing as I've already achieved mad touch typing skills, I'm well on my way!