ZymolHD-Cleanse - 8.5 oz

Do you need to use this if plan to use a clay bar on your car? if so, do you clay bar first, an then hd cleanse or hd cleanse first?

Is this safe on a ceramic coated car?

How many applications per bottle for tahoe and gmc truck?

Does this product do the same thing as using a clay bar and if so what are the advantages of using this instead of a clay bar.