I have been lusting after a portable blindstitch machine (only about $220 US, but it is heavy and takes up space I don't have) so I decided to see just how well I could do with invisible (smoky monofilament) thread and the stretch blind hem stitch on my Brother mechanical sewing machine. While not as fast as a blindstitch machine, I did pretty well once I had the adjustable blindstitch presser foot adjusted so the left swing of the zigzag just barely catches the fabric fold.
Here I show the wrong side (left) and right side of the hem on knit corduroy. I used brown thread in the bobbin to better see what was going on and used the invisible nylon thread on top. After steaming I think it will indeed be invisible.
I got better results on my second try. This is gray print ponte knit with invisible thread on top and black in the bobbin.
I have proven that the industrial blindstitch machine is a want, not a need. However, if I take in enough business doing hems on dress pants and formals I will be able to justify getting one for its speed. For now, it is slow and steady on my home machine. Patience will eventually pay off.