I second the light oil spray as @justgary mentioned above.  Except, what I use was really a saviour when I had my Malibus in the hawaii salt waters - T9 Boeshield is fantastic and maybe some of the best stuff I've found.  If you read up on the product it was designed by Boeing for solutions to NASA  and aircraft components, waterproofing and advanced cutting down for corrosion.  I use this on so many applications, not just the boat/trailer.

T-9 Boeshield - Amazon

Not only do you risk breaking / bending non related parts (strut, cutlass bearings, V drive output brg, seal), the ability to actually hold the boat solidly enough to bend a solid 1.125" steel shaft is remote at best.  You could probably lift the back of the boat and not bend the shaft.  As others suggested, remove it.  Good luck.

I got an email today that Tommy's is selling boats from anywhere to anywhere at the 'Best prices you'll ever see!'  

It is a good time for a new Malibu/Axis if you can get your local dealer to service the boat.   

It's not that hard to remove, especially for a Kansan. Below is when I removed mine, and how I did it. +1 for the dripless shaft seal upgrade.

Check the strut to make sure it isn't bent as well.  I suspect it would bend before the shaft does, and may be a large part of the problem.

After straightening a whole lot of aluminum arrows back in my archery days, I would say that you could certainly straighten a prop shaft.  You could make a roller stand with some ball bearings and use a dial indicator to test for straightness. 

As an alternative, you could turn it between centers if you have a big enough lathe.  Turn it relatively slowly and use a marker to find the high point.

Find the high point and gently bend it on a press stand.  Rinse and repeat.  It goes pretty quickly once you figure out what you are doing.

I suspect you could do it on the boat by lifting vertically against the strut, but that assumes that the strut is where the bend is.  Your dial indicator in a variety of locations along the shaft will help you know if that is true.