The solution to most economic problems is a truly free 'free market'. This is also the case when it comes to a large number of political problems.
The way to eliminate (or at least lessen) the effects of money on politics is not to try and restrict it, since people will always find ways around restrictions. The way to effectively eliminate it is to make the money powerless.
If the government didn't stick its nose into the market, then no one in the market would feel the need to bribe politicians to slant laws or regulations their way.
If we had a simple tax code that didn't try to favor anyone or guide social issues based on some peoples preferences, then there would be no need to bribe politicians.
If we kept our military down to the size we actually need it to be to defend us, rather than try to police the world, then we would greatly lessen the incentive to bribe politicians.
If there were no bailouts to favorite companies or protectionist trade policies or subsidies to certain industries, then there would be no need to bribe politicians.
I could keep going on. It all comes down to this, most of the legitimate grievances that OWS folks have would go away if the government would stay out of things that are none of its business.