frankly when it comes to walmart in this area, from my experience they are rather snooty, i asked to see some knives, was asked for my ID, ok im fine with that, kind of expected it, then the guy said "I'm going to show them to you one at a time." didnt even really give me an option to compare them back and forth, he unpacked and repacked them in between showing me and after i looked at the first one i couldnt find the locking mechanism (it was some type i hadnt had hands on experience with before so i didnt find it right away) and asked him where it was, he just took it closed it can went to get the other knife. so ya mer on wally world
now if they have them in a store and you can buy them you should be legally allowed to posses them in that area but the question comes down to if you can carry it. as an example, here in VA you can own a switch blade and carry it on your property but you cannot carry it concealed in public, but no law is listed that i can find saying i cannot open carry it in public.
so read the laws for the area, call the local LEO offices and ask what the law says or at least where to find all weapons laws for the area
-matt