I think you will find, with a bit of looking, std testing clinics that offer anonymity with an alias. (in fact it is possible to use your sp name for the test results, get a hard copy in that name, and if you were one who has no issues showing the recent results, it would not be identifying real name. Using sp name that you are known by, advertise by, etc, is actually more relevant lol)
I would stay away from walk in general practise clinic or the regular doctor anyway. All too often these places seem to want to talk you out of full testing and/or pre-treatment (say, if you had a possible exposure to chlamydia, typically now they don't just give out the treatment, they want you to wait for test results from what I hear -- that is different than before they would just automatically hand it over)
I think I have mentioned now and then that all new clients should be tested before they see the first sp.
The NZ example is that OHS policy requires that informational posters be prominently displayed on site (meaning the clients are exposed to the information when visiting), and that no uncovered services are provided (in order to comply with the regulations (cbj, covered daty, etc)
It is the hope I believe that exposure to information, and reducing exposure to contact, will have the effect that clients will take themselves for testing and/or be aware of the impact of stds.
On the topic of making it mandatory or not, I am on the fence. If you want legitimacy, it will come with regulations. And part of regulations on such an industry will include health and safety regulations and policies. It is or should be within the right of an employer to require a recent test, and/or to encourage regular testing possibly by having technicians visit the work place, or educational training? Sometimes people say "it's sex, it should just be natural to everyone". Well, it is, but it isn't common knowledge and it is dangerous actually to leave it in the hands of the workers to just go ahead and do it on their own. When I worked in a fitness field, in order to be employed you needed to be certified. IN order to maintain certification, a certain number of working hours per year, CPR/First Aid, and a minimum # of training/workshop hours were required in order to renew certification. I was dealing with people, in a workplace, and it made sense to have the kind of knowledge to help them if they get into an accident, injure themselves, get exposed to something.
I can't think of any good reason not to have similar requirements for sex workers who have to have licenses, etc. Other industries have requirements and minimum standards. If you want to have credibility and reduce the stereotypes, you up the game.