This comment has been sitting in my head for the last hour or so, so let me add this but also invite others to opine:
(Internal mix) airbrushes have bushings that prevent liquids (and air) from going backward along the needle from the paint path. Purposely back-blowing or back flushing (i.e. covering the tip and pressing the trigger) is a common method of cleaning, and I do it myself at times to force air up into the cup to help loosen/dislodge any potential dried bits or chunks that I don’t want to try to push through a 0.2 nozzle. However, doing so does cause air to push solvent/paint into these bushings and can eventually cause a problem. In the years I’ve been using my Badger airbrushes, I’ve never had this problem, and I disassemble mine probably once every 2-3 paint sessions to give a thorough cleaning. IF a solvent (e.g. acetone) reacts with the bushings (e.g. makes the elastomer swell or causes it to break down), (a) it’ll likely be obvious from air leaking past or the needle sticking from a swollen bushing, and (b) the airbrush manufacturer likely either sells replacements or will replace the bushings themselves.
I’d recommend checking out this thread, Tony and Don both have a lot of very good info to share!