Some DIY solutions for dental care are pretty common, such as teeth whitening strips from the drugstore. Although they do not work as well as an in-office solution, they are generally safe.
But orthodontists are concerned about people who try teeth straightening solutions at home to save money on expensive dental work.
People who do not want to pay now may very well pay later and it will be much more expensive to fix. You can read more about why you should not take a chance with these procedures at home.