"Those who write on bathroom walls..."
Cottonseed meal is your nitrogen source. and an acidifier It appears to be available through Amazon if that helps. Any other reasonable sub in would do it. I can get it readily as I am in the Deep South but also use semi-composted goat manure as my N. Any chicken manure product would provide the N and the acidity similar to the cottonseed. My mix is basically goat berries, blood meal, bone meal, Ironite, kelp meal, azomite, epsom salts, lime. It lives in buckets.
I don't make balls - I either use an old ice cream scoop and plunk it on top or if it is dried usually just break off a chunk.