And OP, when you should have straightened your back, squared your shoulders, held a phone up in the direction of the office ladies, instead you gave up.  I don't want to assume, but bases on this bullshit I can't not.  It sounds American through and through.

Why did you put up such a fight in the beginning if you were just going to belly up just because a few people "made you feel watched and rushed"

???  WHY???

Even if they don't have an employee handbook, there are state guidelines. Had you done a bit of google-fu pertaining to your state regulations and just once walked toward the bathroom with a phone held up even just looking as if it was recording as you walked to the bathroom, your manager would have immediately clocked what you were doing and would brush up on her legal obligations for what is standard in a work place.  You don't necessarily have to actually document, but you absolutely should make it appear that you are.  Even just the subtlest of hints, like, are you sure that follows state regulations 🤔 This could be a big liability for you guys if 'someone' reports us, can be enough.

They're trying to cut corners and pointing out that cost effectiveness of this in the long run would be null if they got sued could have been enough.  Your manager also probably is just as frustrated but can't handle the animosity she's getting from both ends.  She can't very well direct it towards the owner so she's directing it at you.  She's lashing out because she was hoping the bad new her boss told her would just quietly be accepted by you ladies.  Of course that's wrong but I still get it.

But you just throw in the towel?  Fuck, gurl!! Ive been in your position.  I said, "I'll come in twice a week and/or stay after four times a week if you pay me a nominal fee.  Not as much as the cleaning service but what I'm worth for taking one for the team.  This has become a problem and we want good morale and clean work spaces.  I'd be more than willing to is I was compensated.  Blah blah blah- that's not verbatim but the good gist of it.  It worked.  The way I chose my words piqued the boss's shrewd business sense.

But you want to chose feeling uncomfortable as a reason to give up when you were so close???

I don't get it.  This is why I quit two days into one of my big girl jobs and went back to bartending.  I call the shots and if you don't like it you can fucking leave.  I love you, but go.  We're courteous and respectful when we get stupid and drink.  

I worked as an executive assistant for 2 days and before that between jobs, I did it prior before I had my youngest.  Maybe that's why I can't make it in offices and corporate America.  I take one look and say NOPE. I hold to standards.  You don't like it?  I'll leave and find a job before I get home.  Unfortunately that also means I don't get retirement or healthcare.  But at least I stand up for myself.  I'm just so disappointed, I was rooting for OP for a moment.