Depend upon the clay and how firm you apply pressure when claying and for how long or how many passes you do over a single section and how thorough your are as you go around the entire car.
Because online enthusiasts tend to be kind of DO or Detail Oriented, I like to put thing into extreme to make a point because it seems this method of explaining things works.
As yourself this question... does claying add wax or paint sealant to the surface of paint? The answer is "no". So what's the opposite of adding? Subtracting or removing.
Pretty safe to say that unless you're using an ultra fine clay, most other clays are going to remove anything sitting on top of the surface. Claying probably won't remove wax and/or paint sealant that is embedded into the low valleys of paint, or pits, pores, or interstices, but if the clay is physically rubbing against the paint then chances are good since it's not adding wax or sealant to the paint it's removing it.
A safe way to remove previously applied wax or paint sealant is to use a light polish by machine or a light paint cleaner by hand. Both approaches will remove any product readily available to the public off the surface plus leave your paint clear and shiny and ready for wax or paint sealant.
If you want something faster like wiping a product on or washing the car with something take a look at the
Griot's Paint Prep .
Some recommend
P21S Total Auto Wash but I checked with P21S for their official recommendation for using this product and they recommend
the last step should be a rinse with fresh water from a garden hose, sponge from bucket of fresh water etc.
In other words, don't just spray-on and wipe-off...
In recent years some waxes and paint sealants are stated to be detergent-resistant, so washing with dish washing soap doesn't guarantee you'll remove everything.
IPA won't remove all polymers, so that's not a 100% solution to the problem but Mineral Spirits usually will.
