Once again this is your OCD speaking, which I think you know.
For over 30 years, there has not been a single reported case of HIV being transmitted during the process of having blood drawn -- ever since disposable, non-reusable equipment became the norm, with never re-use of needles, syringes, etc. Even if gauze had been used on a previous, HIV infected patient, not enough virus would be present or could have access to your blood stream for infection to take place.
Asking how long HIV survives in the environment or on exposure to air is not the right question. However long it is, such exposures do not result in HIV. Nobody EVER catches HIV from the environment in places where blood is drawn or anywhere else.
I think Dr. Hook's comments about deep versus superficial wounds have created new concerns for you. (That's one reason why we do not reply to continued repeated similar questions like this. Anxious persons and those witih OCD often take information intended for reassurance and twist it into additional concerns about even more outlandish transmission risks.) Anyway, think of a deep wound as a slash with a knife, the sort that might require stiches; and then having fresh blood from an infected person enter that wound. Anything less than this has never been known to transmit HIV. In medical personnel who have been infected when providing care to HIV infected persons, it always has involved a substantial injury with a sharp instrument while that instrument was also being used on the infected persons, like a scalpel wound in the presence of the patient's blood. Except for blood transfusion (back in the days before it was prevented by testing donated blood), NO OTHER KINDS OF BLOOD CONTACT, OUTSIDE MEDICAL SETTINGS, HAVE EVER BEEN KNOWN TO TRANSMIT HIV.
Another comment about your original question about the case perhaps transmitted by shared manicure equipment. I agree with Dr. Hook that the case was not proven. But even if that's what actually happened, is is the only such case ever reported over 30+ years of the known worldwide HIV epidemic. That there is only one such report proves how rare such an event is, if it occurs at all. There is no realistic chance you will ever be the second case.
You clearly are obsessed with nonsexual transmission of HIV. You need to work to get past that misunderstanding, probably through professional counseling and treatment. If you only have safe sex with partners not at high risk, and if you never share drug injection equipment with other persons, you will never get HIV. There are almost no such persons in the United States and you won't be the first!
I hope these comments are helpful, and that you get appropriate care that brings your HIV related OCD under control. So let's make this the last question from you along these lines. We discourage repeated questions on the same topic or exposure. This policy comes from compassion, not criticism, to reduce temptations to keep paying for questions with obvious answers. In addition, experience shows that continued answers tend to prolong users' anxieties rather than reducing them, especially among anxious persons or those with OCD -- as discussed above. (There's always another "yes but", "what if", or "could I be the exception" question, right?) . Finally, such questions have little educational value for other users, one of the forum's main purposes. Thanks for your understanding.