As a specialist dental negligence solicitor I have never yet come across "hot tubbing".
In case you did not know what hut tubbing is - it is the practice of dental experts giving evidence in Court at the same time in each others company. This goes against the normal practice of each dental expert stepping up - giving their evidence and then stepping down followed by the next dental expert, and then the next..you get the idea.
Hot tubbing appears to be a Judge led exercise and allows the experts to be asked the same questions by the Court and importantly the other experts can presumably ask questions of each other and respond to each others questions. The thinking behind the process is openness and a primary duty to the court (which is enshrined in the civil procedure rules anyway) rather than adopt a "hired gun" type attitude.
In my view hot tubbing is simply the natural step onward from a joint meeting and joint statements (again enshrined in case management directions in any event).
The danger as I see it with hot tubbing is that issues that may be raised by examination under Counsel may be lost if the procedure is led by the Court. In dental cases especially, Counsel is well versed in the subtleties of teasing out information whereas the Court usually just wishes to cut to the chase and important matters could be missed from a claim unless the parties Counsel are given permission to examine after the Judge.
The Law Society Gazette (10th April 2017) writes that (unsurprisingly) hot tubbing has not yet caught on.