Probably worth noting some aircraft are placarded "Spins Prohibited" for good reason. During certification spins are approach gingerly, often with a spin chute that can be deployed to recover from the spin if normal spin recovery doesn't work. Some aircraft will exhibit raising of the nose and go into a flat spin several turns after spin entry. Some aircraft will become stable in a flat spin and resist efforts to break the spin and recover.

During my PPL training in my Mooney, I accidentally entered a spin, flipping over the top and pointing straight down. Scared the crud out of me. I quietly asked my instructor if he wouldn't mind taking the plane and saving our lives. He did that. But it took about 3 turns and at least red line pulling out of the dive. He opined afterwards that the nose looked to be rising during the spin - - I'm not sure, I was in the fetal position trying not to get in the way of the rudder pedals.

I told him I was pretty much traumatized and wanted some spin training before flying my Mooney again. He asked me if I wanted to be an instructor. I said I don't think so and he said, okay, then we can't do spin training. I changed my mind about being an instructor and we rented a C152 and went spinning. When you spin with some assurance that you might survive, it's unnerving at first but gets to be fun in short order.

I enjoyed spinning my Starduster biplane and Aeronca Champ - both rated for spins. Wish my current Husky or ASH26E was, but unfortunately neither is and I'm not brave enough to be a test pilot.

Counting on intentionally spinning a "not certified for spinning" aircraft to exit IMC is not a good plan. As some have suggested, benign spiral may work in a ship that will do so in benign conditions - inside convective or wave rotor is anything but benign, so I wouldn't count on that either. Getting some instrument training and a gyro is the best approach IMO.

GPS, even Garmin's "panel page", which normally works fine for gyro back up in power planes, would be a poor choice for primary "simulated" gyro info in a glider flying in the kind of wave conditions we get at Minden.

GPS "panel page" wings level/turn, course and speed info is all based on ground track, and in high winds track can be back asswards or sideways from the direction the glider is pointing. I have an instrument rating, so have at least some clue, but think being blown sideways or backwards would present a GPS display that would be all but unflyable in turbulence, and in smooth air, if flyable at all, would be a high workload for sure.

Flying IMC with no gyros is a great equalizer, instrument trained or no, there's a strong risk you'll get to use your parachute or worse.