[dsmith]

if you go the heli-coil route and don't want to take the head off...

The groves in the drill bit and tap are designed to allow waste material to escape. By filling those grooves with grease, both the drill bit and the tap will collect most of the chips -

downside, the greasy chips that escape can be harder to capture,

upside of the downside is that they don't travel - sorta hit and stick.

smith