I'm looking at my zinc sulfate solution and comparing to the PDF you linked...seems like using this liquid to supplement zinc would be slow going. 1 tsp only contains 1.15mg of zinc, so even 6 tsp/day would only be around 7mg of zinc!
I'd say someone should definitely be supplementing some zinc picolinate on top of it if they ever want to get somewhere.
Also, never forget that correcting a deficiency requires different strategy than a maintenance dose. Living paycheck-to-paycheck doesn't leave any $$ to put into savings, much less to pay off accumulated debt! (hopefully the analogy comes across)