Hi...
just to share my experience...
i had a snail infestation, and i refused to use chemical as well.
I bought 4 clown loaches.... clown loaches are very prone to ICH. they gave all my fishes ICH and wipe out my tank....
I got a batch of new fishes, i decided against clown loach this time.... i got 1 tiny puffer.... the puffer started nipping fins of my other fishes... now they are all stress and i have to segregate them...
fish keeping is like playing the sims. but hard cos it doesn't have the tell tale bars. sigh....
i feel that the JUG method may be the best, if you do not want to upset whatever you have at the moment..