Good Job Chris-did you use iron out?
It is possible that water could cause some issues.
You need to put that in your contract so you are protected.
Letting them know is a good idea as well.
Use as least water as possible and bring in some blowers to dry them quickly. do maybe one 400 grit resin diamonds cut and polish.
Honing powder wont give you the clarity. If the stone dries out fast take it to 800 grit.
Sealing the floor with something like dry treat might help-dry claims even after light honing some of their sealer stays in the stone.
Not sure I believe that cause usually after you cut it the sealer is gone.
You could polish dry but I think you should be ok.
One issue to be aware of-if the floor is older and it has some wear you may have a situation when you polish the etched areas they may look better than the rest of the floor.
You may want to consider doing the whole floor as you need to have a uniform finish.