Cross-pollination does not affect this year's pods in any way, except the genes in the seeds, if that is why you are asking it. For the purpose of saving genuine seeds I'm interested in this one too.
I would only want to protect a few pods not the whole plant.
People use different kinds of fine meshed net to protect flowers, branches or whole plants from being cross polinated. I have heard about teabags and small gift bags for single flowers.
