This is something anarchists may wish to consider and/or reconsider. The issue of deferment, of putting off the destruction of the present order, is perhaps the highest problem for anarchists to tackle. On one hand there are all of these practices that reify struggle, that represent and act out a struggle that should be coming from people without a middle institutional agent directing them (activist groups, community organizations, unions, etc.). What could be considered an authentic battle of active agents against the forces of the social order is often intervened by and then controlled by institutions, some of which feel they are a necessary element to destroy the present order (revolution, insurrection, overthrow, etc.).
On the other hand, anarchists in most places fear taking authentic action individually. Often shot down by rivals (leftists, liberals) as adventurists, voluntarists, substitionists and so on, anarchists let themselves be demoralized by these forces, perhaps because even taking the first steps to bringing destruction to our enemies is a scary proposition. If they made it past the reifying practices, taking individual or collective action with others to wage personal war against individual elements within the social order (elements being institutions, individuals, infrastructures, materials, forces, etc.) has few allies among those that hold sway over the definition of struggle (demagogues).
So the solution to these issues would be to perhaps re-examine some approaches and in this case (to answer your question) open ourselves up to defining ethical business ownership. We already can say all businesses should be destroyed and those that support them have a tendency to defend their business and more readily accept the recuperation of struggle (healing present grievances by those disempowered by the social order with the social order and ending struggle instead of pushing it beyond a mere challenge to domination).
However, we do have "friendly" businesses, one of which hosts this website, as an example. There may be no ethical way to manage businesses other than irrational ways, emotional ways. Saying these are my friends and they support me, so I support them is irrational. An ethical approach would attempt to apply shared standards based on the theory and activity desired by anarchists.
Some forms of anarchism have attempted this, such as mutualism and some forms of market anarchism. Their attempts have largely been dismissed as pro-capitalist or only a possible practice for a minority of people. Also, as complete systems of thought, as ideologies, there methods are tied with a progression towards an end. Mutualists feel they are working towards an anarchist society by using and building ethical business practices. I would disagree, but perhaps there is something here. A cultural norm perhaps that crosses outside of ideology where we reject the premises of mutualism, but accept its practices despite their inherent flaws and lack of purity.
I am a poor working class person, so I can identify with your problem, especially when some anti-capitalists hold jobs that propel them into the middle class or beyond. If not that, many also come from wealth and they can afford ethics in business practices or to demand a rejection of all business ownership. If I and perhaps you start a business, the risk is to lose everything and become homeless. Investing in a business is also very expensive and trusting ownership outside of ones' self is difficult to give. However, with the right kinds of associations, an ethical practice can occur without risking your self and perhaps your family's well being.
Business associations exist now that propose ethical business practices. What is ethical to them is probably not an anarchist view of ethics, but it does provide a model for the possibility to do so. So while we might not be able to achieve a 100% worker cooperative business model, we can help each other stay friendly to the cause of destruction.
Your problem with exploiting workers is indeed a very real problem to be considered by any anarchist seeking to start a business and an answer is to create a support network for friendly businesses and define business standards according to your associations. And since even with worker cooperative models we are merely managing our own exploitation, it isn't necessarily the strongest criteria for friendly business creation.