I looked at the articles in question, and the independent studies are not so independent in the 2007 study. The laboratories were commissioned by the paraffin distributer to conduct the studies, so there is a bias.
The other study from 1996 that was posted on their site was also not completely independent as a big comment at the bottom of the article refers to the paraffin company for their assistance in searching for relevant information. Could the information they provided have steered the study in a particular direction? (Just thinking out loud).
Another point from the 1996 study, if paraffin wax can not harbor bacteria or fungus then why did 2 of the 22 samples taken from the salons contain significant levels of bacteria and 4 of the 22 have a significant amount of fungal growth? I noticed the results were brushed over for this but it is still paraffin and still harbored bacteria and fungus, regardless of the brand!
Sorry it is the researcher coming out in me!! Personally I think that there is much more research needed that is independent of brand and duplicated several times, under several conditions to reach any firm conclusions.
So I have to say that I am not convinced from these studies that double dipping into a communal paraffin wax bath would be free of pathogens that could not potentally be passed on to another customer. IMO