No. Lesions are usually for HIV; at least that's what we classify them. HSV-2 are fluid filled blisters. The blisters contain water, the virus and white blood cells, or t-helper cells attempting to fight the virus. Once a person builds anti-bodies, then they disappear much faster. Blood tests now have 99.8% accuracy and are the standard. However, we would usually swap the vagina (and around), inside the penis (urethra), the shaft/head of the penis and anal canal if there was anal sex involved (very common nowadays).
In order to swab the actual blister, that would mean having to pop it, which could have the virus particles all over the place (due to the popping and fluid pressure). It's one of the reasons most healthcare facalities prefer not to go that route. Plus, it's not safe for medical staff. So, the IGG blood test is the test of choice. There is also the Western Blot test from University of Washington; but it's very expensive. That is also an option for the patient to consider.
FYI: A HSV-2 test is very common during pregnancy to rule out HSV-2. Should the mother have HSV-2, there is a good chance she can pass it along to her kid if she's not on anti-viral therapy (Valtrax). The kid could contract HSV-2 during the birthing process and may not live since it doesn't have a strong enough immune system to fight off the virus on it's own. This is why HSV-2 is no joking matter for ladies.