Mark page's field as unchanged (not dirty) from code

Is there any way to mark a field/set of fields as being unchanged on a form page from code? We have some parameter fields which do not link to the page's data source, and have a separate button for managing saving this data (we are on 8.2.0, so cannot use multiple data sources for the same page) but at the moment when saving this data the fields will remain "dirty" and so the regular Save button will be shown & a warning will show if the user tries to navigate away from the page. What we would like is for the custom parameter saving button to clear those fields when it's finished and then mark them as unchanged/non-dirty so that this is avoided.