Stop it posting about something
Add a subject to the never-post list and it stays off it, in every business you run.
Settings has a list of subjects it will never write about. Add one in your own words — whitening offers, anything about other practices, prices going up — and it does not come up again.
You are naming a subject rather than banning a word, so you do not have to think of every way of saying it.
The list is yours across every business you run, not one list per account. Somebody with four businesses does not have to say the same thing four times.
Take a subject off whenever you like and it can be written about again. Posts already written and approved are not changed by adding to the list, so look at the week if you have just added something that was about to go out.
If this did not cover it, ask. A person reads it and answers the same working day.
Ask about this