It works quite well in the Nordic countries, where capitalism is harnessed by the people for the public good. Capitalism doesn’t have to corrupt democratic governments; the people simply have to decide who shall be the master: them or corporations. The power of capitalism to corrupt governments can be significantly reduced by a number of simple steps:

• Prohibiting private funding of election campaigns and all campaign donations; publicly fund elections.
• Limit electioneering to specific times and restrict paid advertising for political purposes.
• Ban lobbying by corporations.
• Prohibit any government official from working in an industry he was responsible for regulating or negotiating with while in office for 10 years after leaving office. (If you don't like that deal, don't go in to government – it's not for people looking to make a buck.)
• Explicitly assert that corporations are not people and have no political rights, and especially no right to free speech. Speech is for humans.
• Criminalize influence peddling both in and after office.