My microdermal anchor was inserted into a pocket formed using a dermal punch for the initial hole and then a needle to create the pocket, although I'm afraid I can't remember the sizes/gauge. Mine was in the hollow of my throat and I wore a plaster over it when I slept or bathed, but otherwise let it breathe. I soaked a cotton bud or pad with warm SSS and rested that on the piercing until it was cool a couple of times a day, and the healing was uneventful.
I believe that my microdermal anchor rejected after one-too-many times snagging it on my clothes or hair, and it was very painful because the whole area swelled up including where I had healed through the anchor. So my main advice to people getting microdermal anchors installed is to be very careful with catching it even when you think it's healed and secure.
Current: 1x 3mm helix, 3x 2mm helix, 1x 1.2mm helix.
1x 6mm lobe, 1x 3mm lobe, 1x 4mm lobe, 1x 2mm lobe, 2x 1.6mm nies/slip
1x 2mm nipple
4x skin divers
Retired: 2x snug, 2x helix, 1x microdermal, 3x skin divers
Wanted: 1x Christina, many more skin divers, scarification