I make rejuvelac all the time with a variety of sprouts, including buckwheat, rye, rice, amaranth, quinoa, and even lentils. If you are asking if you can make rejuvelac with the first soak of unsprouted quinoa or any grain, I would say it's not worth trying. There are enzyme inhibitors and other undesirables in the skin of grains that should be removed by soaking before sprouting and fermenting for a good germination rate. At the very least you should also rinse them really well after the initial soak, which isn't necessary after the first batch.

My method uses 4 half-gallon mason jars. I begin by first rinsing, removing bad grains, and soaking (usually 8-12 hours), then sprouting for 1-2 cycles (allowing the grains to sit in a strainer suspended over a bowl and rinsing every 8-12 hours). After soaking again in 2% lemon juice for 30 minutes to sanitize, I rinse again with filtered water (tap is also OK, but just for rinsing) and add to the mason jars along with some blended, strained organic local cabbage and the juice from 1/4 of a lemon. Fill to about 1 inch from the top with filtered, spring, or Ionized Water then vacuum seal (the reason for the mason jars) using a home vacuum sealer with accessory hose and jar adapter. Lactobacteria are anaerobic, so low oxygen gives them a competitive advantage. Skim the top and pour through a small strainer into a glass container and optionally vacuum seal the product if making large batches. Always refrigerate.

It generally takes 36-48 hrs at 70F and about 24 hrs at 80F for the first batch, where I sometimes need to reseal because the fermentation gases break the vacuum seal. The subsequent batches might only take 24 hrs at 70F or 16 hrs at 80F, depending on how much of the concentrated stuff at the bottom you pour off the first time. Never a bad batch yet with this method (100+ gallons)