First, if you have a Ph.D. degree, an employer has to pay you a Ph.D.'s salary in your field. Of course, if you want to a salesperson, you don't need to mention your Ph.D. degree. But I don't think that is your intention.
Second, if you mention your willingness to take a M.S. level job, an employer would label you as a loser, who can't take on big challenges and responsibilities.
Third, you won't be happy to work as a M.S. level employee simply because it's hard to swallow your pride as a Ph.D. holder.
In a nutshell, do not take the path you proposed unless you are desperate and need a last resort. Why did you study for a Ph.D. in the first place? Without a clear purpose, no matter how hard you try, the end result would be meaningless.
One muggle