My career was as a conservation officer first for the state of Maine, as a Coastal Warden, then as a fisheries enforcement agent with the National Marine Fisheries service.
I worked at the Lobster research station in Boothbay Harbor Maine before becoming Captain of the patrol boat Explorer.
Those scientists at the station assured me that Lobsters do not feel pain as we do.

If you want to do them in without "Pain", simply put them into FRESH water for an hour or two. Overnight is better.

By the by, what do the Germans know about Lobsters?