A simple DIY bubble cloner is my chosen method. I made all of mine with repurposed coffee "cans", $12 aerator pump, and a few bucks worth of tubing and cloner plugs... runs with plain tap water.....Some pumps run 2 buckets even....Most cases, by 7 days they have tiny roots.
One key aspect of getting clones to root quickly, will be the state of health, the cut is taken from. A plant that is not firing on all cylinders, will produce cuts that can be a beeeyatch about taking root in time, before they become down with the sickness....