At home I print SLA. I did the whole ear danger enchilada....go to home Depot, get caulking silicone I tube.....I hear you scrolling away....then I tested the quick silicone recipe where you mix flour into the caulking. Once tested and guaranteed to work, I mixed a batch and stuck it in my ears. I used a portion of a foam plug to plug the inner ear shut. Then with a stick in my mouth I waited for 15 minutes. The result were excellent impressions of my ears. Then I used meshlab and my DSLR to do photogrammetry and output an STL. Then to freeCAD to output a STEP file. Next to UGNX to create a surface model of the IEMs. I ended up making one and flipping/mirror to make the other and it worked better than the impression of that one. Did some test prints in gray for fit. Then I bought some cheap earphones and took the armatures out to make the IEMS. I have several sets now. One was a simple cast on places earphones set. The others are using the IEM as a hole to which they just snap into place. And I got another where I bought cheap IEMs and I modeled the inner parts so I could just use them in my IEMs. freeCAD would probably have worked too. The finish of the part doesn't have to be perfect because you're going to sand it and polish it or sand it and dip it into resin to then cure with a UV lamp. I'm super satisfied and the thing is that I can pretty much design any other thing that attaches to my ear...as funny as that sounds.