You could provide your own cursor and make it one pixel wide.

Excerpt from the perl Tk FAQ:

$mw->configure(-cursor => 
     ['@' . Tk->findINC('demos/images/cursor.xbm'), 
            Tk->findINC('demos/images/cursor.mask'),
            'red', 'green']);

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In reply to Re: Disabling the mousecursor by busunsl
in thread Disabling the mousecursor by Jouke

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