Your item has been waxed and buffed, but if it needs to be cleaned place the item on a flat service and gently buff it with a soft cloth. Do not use vinegar, windex, or other glass cleaners as it will break down the wax. The wax acts as a natural sealant to slow the natural oxidation process of the solder and lead used in creation of the piece.
While I do wax and buff, from time to time the solder or lead will oxidize and leave a whitish substance on the surface. If this happens, gently wipe the area with a soft cloth (microfiber or an old tshirt work great), or a soft toothbrush. If this doesn't work, please contact me.
Best practice would be to reseal your piece at least once a year with a car wax that contains carnauba wax. Simply put the wax on a soft cloth, polish the metal and glass surfaces, let it dry for 10 minutes, then buff with a soft cloth, and voila! Ready to shine for another year.
I never recommend using suction cups to hang your new piece. Suction cups deteriorate over time and may fail; I suggest using a nail or hook in the framing around your window and hanging your piece from that.