If your bow is shooting you should have some finish on the back at least, this will stop future checking. Filling cracks with superglue will stop them, no need to clamp anything just fill them until you have a puddle of glue on top of the limb. Scrape the puddle off after the glue dries.
I had some very dry osage in my garage one time, it had been cut for years and had no sealer on the back. We had a day when the relative humidity dropped to a fraction of what it normally averaged and my wood checked. The strange thing is I looked at the wood a week or so later after the humidity had returned to normal and all the cracks had closed to the point that they were invisible.