Every time I restring I use a microfiber cloth and rub every surface down on the body, neck, and fretboard (I really try to get as much of the dead skin and grime off the frets), but it's been a while since I've done a full on real deep clean. Honestly, I've only really ever done a true deep clean once on my main bass and that was when I switched out the pots and had the bass nearly fully disassembled anyways. I polished the body, used lemon oil on the frets and fretboard, and the back of the neck got a good cleaning too. The other two basses I have not done that with but have wiped them both down plenty.
But then again if I accidentally spill beer on my bass or something I will clean it up pretty much immediately after the session
But then again if I accidentally spill beer on my bass or something I will clean it up pretty much immediately after the session