Questionable

So a lot of the work I've done recently has been for general entries competitions or submitting multiple designs to a single company, after which they pick one or none for you to complete for use on their product. I've thought about posting these images that were not used but I would like to show them around to some other companies and see if they would like to pick them up instead since most are not company specific. So here's the dilemma, how do I get them interested without showing the designs away at every shop and two weeks later seeing rip-offs from everyone who didn't mail me back and just had an in house artist do a cheaper version? Where are the submission guidelines for companies like t-shirt/clothing and sports gear like skate/snow/surf boards? Any ideas, suggestions?