Silk
Nappy Care (Bi-Lo generic version of Napi - San) is lemon scented, as from memory Napi-San is as well. I only use guess work when measuring it out (it suggests 1 capful per 7 litres of water) as i sterilize in the bathtub, and I barely notice the scent. As for rinsing, I give the fermenter a quick rinse, but don't rinse the bottles. I haven't noticed any affect on either the flavour or aroma of the brew, however I am far from a conisseur and others with a more attuned taste may or may not notice.