BW - is the Swiss Ball you talk about one of those heavy inflatable beach ball things? I have one of those and when I can't get out on the recumbent to make my back feel better, exercises on that big ball thing really helps! I just should do them more often!
I personally don't believe in stretches, etc. Not saying not to try them, just don't do anything for me and good solid well done research on their benefits is lacking, though admittedly tough to do. But try them - if it feels good, do it!