Interesting to know many postings recommend using pieces of dead prawns or fish to speed up cycling. In the past I like this method but not lately. We all know that dead animal fouls up the system quicker and sometime can go out of control. Imagine leaving a dying anemone there for a week.
IMO using small fishes or animals seem more like a natural approach, so called 'let nature takes its course'. They produce shit, ammonia, nitrite, nitrate....
I don't recommend buying expensive fishes. Go for cheap damsels or clowns, snails, hermit crabs, etc. Eg. for a 3ft tank, 3-5 damsels is good enough.
A month ago I started my #7 tank (I think it's #7 over 17+ yrs) and I got a few clowns to do the job. Put them in after a week after introducing LR and they survived. Nevertheless, don't omit testkits!