Alright, let me explain. I have played the Ukulele for about a year now. Long story short, I accidentally learned to strum with my left hand instead of my right. (For some reason, I could tune the ukulele backwards without having to get it re-strung.) Now, I want to move on to more complicated stringed instruments such as the Charango, that have varying string thicknesses and you can't tune backwards. What's the best way to swap the hand that I use for strumming? (I'd rather not have to get my instruments strung.)
If you swap hands, you really better swap stringing as well. Look at it this way: you should be replacing your strings (on ukelele, guitar, and most other strummed/picked instruments) on a monthly or shorter basis anyway.
Now, as to switching strum hands: it's like the old joke about how to get to Carnegie Hall. "practice, practice, practice." It'll be awkward for a while, but after that you'll be an ambidextrous player.
Please be advised that string instruments are usually built to cater for a particular distribution of string tension and pitch, and that they also are "broken in" with such a distribution. Also almost any replacement instrument or instrument you test out will be strung in "standard" manner.
I play chromatic button accordion, and when I am meeting up with accordionists, 95% instead play piano accordion, and of the rest, more than half play B system whereas I play C system (which is somewhat akin to having the frets of a guitar in reverse order, not that this makes a lot of sense). As a result, in such gatherings I am severely limited with regard to letting others test play my instrument and checking out instruments of others.
So unless there are very compelling reasons, I strongly recommend to take the plunge and change to staying with the flow. It also means that if you are playing more complicated music from staff or tablature, your anatomy will be aligned with that of the composer/arranger, making it less likely that music written for your instrument becomes physically impossible for you to play, assuming that you are a human player of course.