They did all kinds of wierd things like this. Tiny grooves, V grooves, alternating grooves, etc. I doubt that most of them worked very well. Hard for the patch to cram itself into those tiny grooves. I have photos of an early 19th century German rifle with "Haar-nadel" rifling. Something like 33 narrow, deep, square grooves. I can't imagine that it would hold a patch well, but this particular gun probably wasn't shot much anyway.
Most of them had perfectly normal round or square grooves.