You must be completely unaware that EVERY tank on EVERY military aircraft is used to take fuel samples every day. The fuel is analyzed for contaminants, but most importantly checked for water because it can foul an engine's ability to perform. Real fuel ran down my real arms when I drained a quart of real fuel into a real jar for every real fuel tank.

I have also been internal to an aircraft's fuel cell and sopped up remaining fuel with real rags and used real fans to dry/evaporate the tank for maintenance to fix a real leak.

I have also witnessed a fuel dump on the ground where the wing fuel dump was activated inadvertently creating a massive real fuel spill.

My experience is first hand, direct maintenance over more than 10 years of time. Yours?