The easy way of doing ten to twenty at a time is to put a couple of wood
strips in a big plastic garbage bag laid on its side. Then stack in 10-20
excluders. Then two more strips of wood and a piece of plywood. The wood
keeps the garbage bag from melting on the wires. Tie the neck sack tight and
set in the sun on a bright sunny day. Use gloves to remove and give them a
slap while still hot to remove any wax left.
I would not scrape wax off with a hive tool as there is a thin layer of
electroplate on the wires and when scratched off they will rust. Rusty
excluders tear bees wings!