I don't think your "friendly service advisor" is out to harm you, but is just a little sloppy with English. As an example, suppose I advise you to reset the burner on your hot water heater by disconnecting the gas line and letting all of the gas escape. Obviously, following those instructions literally would fill your cellar with gas. However, turning off the gas supply first, close to the heater, then opening the line downstream of the shutoff, would only bleed what gas was trapped between the shutoff and burner control. Much different.

Likewise, if you disconnect the negative battery cable from the battery, then momentarily touch the battery positive terminal, no current flows from the battery, because there is no contact to the negative post. However, if there is a small capacitor in the ECC to retain its memory. it would be discharged, resetting that memory. The amount of current would be small, similar to the amount of gas that would escape in the water heater example.

Another Brickboard contributor reported his ECC stopped working entirely after replacing his battery, which to me is no different than disconnecting and reconnecting it. I don't think I would try it. Disconnecting the ECC overnight should have the same effect, allowing any memory capacitor to discharge.