I prepare my medium - currently using rockwool and trying rapid rooters - I wet my rockwool cubes in chlorinated water and put the hole in (I set them upside down). I cut at angle, dip, scrape, and insert into the medium, just about that fast too. One at a time.

Depending on how old my dip is I get up to 100%....when takes get slow I toss the dip and get a new one.