I've seen where there is a device to aid with bladder control and perhaps I don't know enough about ED to put this into perspective; however, would this be something that could be modified to help with ED?

This would not help with ED.  The incontinence that comes with prostatectomy is due to an interruption of the muscles of continence.  The impotence that comes is due to nerve damage and sometimes with the addition of vascular problems.  (It is not always simple but the three anatomical problems with potency include nerve damage, insufficient arterial inflow, and venous loss.  Man times, a single correction --a medication like viagra which works on the arteries-- can be enough to aid in potency even when the venous loss and nerve problems can also be present.)