How to make a UIWebView in a table cell fill the ugly grey bit with rendered data

gistfile1.m

@interface UIWebView (WebViewManualRedrawSupport)
- (id) _documentView;
@end

@interface NSObject (WebViewManualRedrawSupport)
- (id) _webCoreNeedsDisplay;
@end

@implementation MyTableCellContainingAWebView (GetRidOfUglyGreyBlock)

- (void) setWebContentNeedsDisplay
{
    id docView = [_myWebView _documentView];
    if ( [docView respondsToSelector: @selector(_webCoreNeedsDisplay)] )
        [docView _webCoreNeedsDisplay];
}

@end

@implementation MyTableViewController (WebViewRedrawingSupport)

- (void) scrollViewDidEndDragging: (UIScrollView *) scrollView
                   willDecelerate: (BOOL) willDecelerate
{
    [contentViewerCell setWebViewNeedsDisplay];
    if ( [[self superclass] instancesRespondToSelector: _cmd] )
    {
        [super scrollViewDidEndDragging: scrollView
                         willDecelerate: willDecelerate];
    }
}

- (void) scrollViewDidEndDecelerating: (UIScrollView *) scrollView
{
    [contentViewerCell setWebViewNeedsDisplay];
    if ( [[self superclass] instancesRespondToSelector: _cmd] )
        [super scrollViewDidEndDecelerating: scrollView];
}

@end

Is there a way to do this using only documented methods?