I didn't properly express myself. Yes, I think a right side IWB will properly hold the gun on the left side *IWB*, cross draw. However, the angle will almost certainly be problematic.
What I was referring to was taking, for instance, the IWB right hand holster and using it for *outside* the pants, *left* side carry. Unless you're talking about a cheap "universal" holster which works *everywhere* poorly and *nowhere* well, this conversion is usually ill advised.