I’ve been a huge fan of jumbo plastic cable ties as corset boning for a long time. The only real downside to them is that they can get sharp corners when you cut them, and those corners will eat through fabric over time. I used to file them down with a nail-file, but that takes time. There’s a faster, easier way….
“Stay Stitch inside the seam allowance” is a fairly common instruction in patterns. Generally, stay stitching is used to make certain that the fabric of a garment will not stretch out during the sewing process. It’s also a dandy cheater hem, which will fray (but only so far – it’s a controlled fray). Sometimes, that’s exactly the look you want.