"Love motels" aren't great for making/following rules. So don't even count on them doing what the last shift said they'd do. Furthermore, most don't offer in-and-out rentals. (At most places leaving means checking out.)

Pay up when you get there.  Or at the end of your rental period.  Then be sure you're there to prevent the maid from preparing the room for another resident.

It's best not to try this on a Friday or Saturday when the rental period is four hours.  Instead of the weekday 24 hours.

If you are talking about the specialty suites, then yes for sure.  The secret is getting into one...then you have control as they do not take reservations....so once you are in you have the option of staying the next day and they won't rent to anyone else.