The easy solution is if an employer offers low wages NOBODY applies. Leave the job unfilled. HOPEFULLY the business struggles. Let those jobs sit there unfilled. Some low life's would then say "hey there are jobs and nobody is applying and this is what's wrong with america.". Those folk should be shunned.
And you're getting to the heart of the 'union thug' mentality behind minimum wage laws. The reason your suggestion won't work (or won't work well enough to satisfy 'reformers') is because some people would be willing. Some people need it more, and have less to offer in skills and experience, so they'll take the jobs even if most people wouldn't. It's these 'scabs' that are the real problem and minimum wage laws are designed to thwart them.