I searched for literally weeks to find a pure ammonia source and finally found "clear" ammonia at Ace Hardware. It was a "no suds" type that others use. The cycle went well and I did a 90% W/C the day before the fish arrived.
Once the fish were in the tank, Ammonia always tested 0 ppm. Nitrite spiked a bit for a few days, so I did daily 50% W/Cs and used salt to protect the fish. I am told that this Nitrite spike is normal (as the Ammonia-eating organisms establish better than the Nitrite-eating organisms when using pure Ammonia for fishless cycling). Anyway, after about three days, Nitrite went to 0 ppm where it has remained ever since.
Nitrate has stayed very low, owing (I think) to the relatively low bio load in the tank and the frequency of W/Cs.
roadracr