I do use a tooth brush to get wax off. I do not use one to put wax in the cracks. When I wax, I start wiping the wax off before the wax drys hard. With the micro fiber towel with simi wet wax is how I do the creases. There is enough wax on the towel to do the job.
The rock chip areas, with a blackish paint
, a light toothbrush and some QD will help not seeing the wax in the chip areas.
When the time is right, you will want to do the complete process.
Again IMHO, your car looked real nice in the pic. If you put the paint cleaner on, it will strip what is on it now. I might take some QD to the surface to remove spots from washing in the heat, then two thin coats of wax done in small sections, not allowing the wax to dry. This is just my thoughts.