I saw this post a few days ago, (I did try planting some clovers and had very little success) it was very dry, (had a time finding it again).
but I think when they talk of scarifed seed, my guess is it could be done by hand on a few seeds, I think they either use chemical of some type of machine, to do it,
but a number of years ago, I was talking to the director of the FSA and when he was in collage or just after one of the jobs he had was with a large state park, and of the jobs they had was fill in areas where the grass was damaged, and under normal situations it could take up to three seasons, for the grass to come up, so they would lightly moisten the seed, then freeze it (in chest freezer), and then after it was froze good, take it out and let it thaw, and then when thawed, refreeze it and thaw it for at least three cycles, and then plant it. and most of the time it would come up that season,
(just a thought, been thinking about making and trying this machine for dehulling or for threshing small batches of grasses and small grains, but have not tried it,
but the thought was to take two wide tires and put on axels, (use air pressure to control the pressure between the tires) but hook the shafts together with roller chain but drive the axels with sprockets that would be off by one or two teeth, so they are not rotating at exactly the same speed, thus with a small speed differential, either rolling the seed, to dehull it or thresh it out of hulls, (now I do not know if some thing like this would "polish", " scarifed" or not,
some of the other Ideas I read about is using hot water, (not boiling) for a few seconds, and chemical acid treatments, If one had time to test methods, one could try to see what would work with destroying the seed,
but the freeze thaw method is most likely the safest, but one may still want to test on a small batch before committing the entire amount to the process,
Good luck on the planting,