Java síce nie je moja šálka kávy, ale ak by som nemohol použiť regulárne výrazy, nerobil by som to po písmenkách:

private String clean (String text)
{
	String result = null;

	if (text != null)
	{
		int pos = 0;
		int ampPos = -1;
		boolean inside = false;
		StringBuilder temp = new StringBuilder (text.length ());
		
		while ((ampPos = text.indexOf ('&', pos = ampPos + 1)) != -1)
			if (inside = !inside)
				temp.append (text.substring (pos, ampPos));
		
		result = temp.append (text.substring (pos)).toString ();
	}
	
	return result;
}