If you're using a control that's designed to be bound to a datasource, you should always use it in that manner. If you want to "clear it" and so-forth without affecting the underlying data-source, plan to load data into the grid (and to save data from it) programmatically. In other words, your own code.
Even though data-aware controls are convenient, they're convenient only when used for their intended purpose ... and a headache otherwise. Funky code that "you managed to get it to work" and a slew of maintenance problems thereafter.