Table showers alone aren't per se illegal, but they can become illegal if it becomes a sexual service. Typically, a table shower is given to wash the body prior to a massage, and then the person is given a massage. However, if there are sexual acts, there are legal issues. As a nurse, you are not breaking any laws by providing baths for hygeinic purposes. Obviously, these cannot be sexual in nature. If you have any concerns you should ask your supervisor what the rules are for the hospital.
I agree with my colleague. Baths in general are part of your duties as a nurse or healthcare provider. However, like anything else in this world it could be illegal if the touching became Lewd or lascivious under Florida law. It is always a good idea that you have help when bathing a patient who can serve as a witness to the appropriate method of bathing. Always be aware that a patient can complain that the "touching" was inappropriate so cover your bases if the patient is handicapped or has mental health concerns. Good luck!!