It just depends on your school. There are some surgeons, as you likely know from your time working in immuno-oncology, who are heavily involved in wet lab research just not at every center. However, unless you're pursing a PhD, I think you are very unlikely to be seriously considered for a meaningful basic lab project as a med student, as you just can't do anything useful putting in 5-10 hours/wk on a project.
Ultimately, I always recommend that people listen to the advice of their mentors. So rather than trying to force your way into a wet lab project, I would identify a mentor in the ENT department first and then ask them what kinds of research successful applicants from the school generally do. Particularly at this point, you should not be picky on the project or the type of research, you just want to become known and show that you are smart and productive. If you can clear those bars then you may be able to direct the kinds of research that you choose to pursue, but for your first interaction with a new group you should take whatever project you get and do it quickly.
EDIT: I think having some complementary research in a field like Allergy is fine, but for a highly specific field like ENT the majority of your research should be ENT-focused. And again, I stress the most important first step is just finding a good mentor and listening to their advice.