Diamond White is a hard wax so you will struggle to apply is properly by hand. Apply it with a foam applicator pad. I found the soft side of a german applicator was best for DoDo hard waxes.
Light Fantastic is the equivalent soft wax that could be applied by hand. I prefered the german applicator again for this.
DoDo Juice SN applicators (finger applicators) are good as well, ideal in fact for the panel pots.
Give the applicator pad a light spritz of QD before swipping over the wax, it helps stop the pad absorbing too much