yeah, that's sort of the conundrum, innit?
however, you CAN talk to previous employers, or give them a contract/trial gig first, or spend your interview time asking questions about said ethics/discipline instead of asking "lol how u reverse a sequence of bits in 3 operations or less lol"
the standard interview really is a tradition, not a necessity -- the best information comes from interacting with the applicant, period, not from the answers to the questions