don't reasoners use DL?
Not necessarily. They use all kinds of logics, some of which are DLs, some are not.
If it is possible, what configuration of settings should I use in Protege (or other software of your suggestion) in order to do this?
I'm pretty sure there is no such pluggin for Protégé. But if you really want some fun, use a text editor and write your ontology by hand. There are many syntaxes you can use: the functional syntax, the OWL/XML syntax, the RDF/XML syntax are all normative. In addition, you can use the Manchester syntax, Turtle, N-Triples, JSON-LD, that will be future recommendations for writing RDF (and therefore OWL). Or the more exotic RDF/JSON, HDT. Or again, more "powerful" syntaxes like Notation3, TriG, TriX, NQuads. Plenty of fun!
In any case, if you would like to write in the DL syntax, you would need to use special Unicode characters or special commands like in LaTeX for instance. And the parser that deals with it would have to read those characters or commands. Not ideal if you are programming. But you can always use the DL syntax in your writings.
BTW, the current standard Web Ontology Language is OWL 2. Its DL variant (viz., OWL 2 DL) is based on the even more irresistible SROIQ.