I've also heard them called "deep-well" sockets. I have a set of these ("Husky" brand, probably imported) that have served me well for many years.
Most of the pedal servicing i've done has been on MKS pedals on my folding bike. Once the plastic (
) end cap is removed, a 10mm socket reaches the locknut (this doesn't have to be deep-well), and a 12mm (or maybe 13mm... it's been a while) reaches far enough in to engage the cone. There's a non-rotating washer between the cone and locknut, so it's not necessary to be able to hold the cone while tightening the locknut. If the adjustment winds up a little too tight, the cone can be backed out against the locknut. It's easy.
I have Shimano SPD pedals on a couple other bikes, and as
Iride01 said (post #2) the bearing assemblies come out in one piece and don't have to be disassembled for lubrication. In the case that adjustment is needed, the deep-well sockets can be used in the same way.