LARPwashing is the practice of misrepresenting historical movements or figures by projecting radical political ideologies onto them, usually done by individuals who advocate for such ideologies without engaging in meaningful action. It can be seen as the opposite of whitewashing. Where a whitewasher might elide the less savory aspects of a figure like Nelson Mandela, a LARPwasher will try to amplify them in order to make the figure seem more edgy and radical.
A larpwasher might, for example, insist that Apartheid in South Africa was ended solely through force of arms, ignoring that the ANC quickly abandoned terrorism in favor of compromise and reconciliation with the National Party. But the most common variety of LARPwashing involves insisting that the civil rights movement in the United States was largely militant, rather than nonviolent.
Bro, shut up. MLK was not a militant Maoist, you need to stop LARPwashing.