What you might look at also is trying to block the wing in the way that you want it to dry, then use the thinner. Good luck, and tell us how it goes...

I have had to straiten many wings that have warped on me over the years and most of them after putting the planking on. I finnaly figured out if I preformeded the balsa before gluing they would come out straiter. I am straitening out a wing now that was warpet by the planking. It was warped so bad that when i tried to straighten it I had to cut the ribs on the side that was oppesite of the stress. after I cut the ribs it would straighten easier, Then I soaked all the wood with water and blocked a wieghted it so that it was slightly over strait so when it dried it will move again before the wood will settle in the right place. sometimes you have to do this more than once to get it right. I now have the wing straight and ready to cover. I have also straightened wings that were already finished by clear doping an twisting and heating them at the same time. Takes a lot of patience but can be done. I have also cut the covering off on one side. with a wing that was crooked from stress  of the sheer webs. I also had to cut the sheer webs out and soaked and straightened the wind with a 2x2 and wieghts. It worked and the wing flew quite good afterwards. Don't be afraid to try stuff. It is a lot faster than building a new plane.