My technique for getting crickets into viv was:
I kept them in a large plastic tank with a small opening lid in the roof full of egg boxes, scrunched up paper loo roll etc.
I then had a tall thin plastic tub, or just cut top off bottle. Tall enough that they can't jump out.
Lower tub into tank via lid in roof, lift up an egg box/loo roll into tub and shake. Crickets that are hiding then fall into tub, but can't jump out 'cos too tall.
Remove tub, add any supplements, and tip into viv.