I've use vocaloids for making sampling most of the time, it's great for making chords, pads, choir, ambiences/atmosphere etc, but for something like chop chop, stabs, plucky sound, i found out that vocaloid are much inferior to the voiceloid.
You can use voiceloid as a instrument sound by write some non-lexical lyrics like ぱー , お〜, ノロ, ピカ , コソ, なで, ペロ, バタ, ペロ etc.
And chop it, fade it, comp it and put it on your midi pad and have fun.