My method to get these into recovery mode is as follows.
# Plug a lightning cable into a PC with iTunes or a Mac. Leave the iPad disconnected for now.
# Turn off the iPad.
# Press and hold the home button on the iPad.
# Keep pressing and holding the home button as you plug in the USB cable.
# Keep holding the home button until the recovery mode screen appears on the iPad.
If it won't go into Recovery this way, try another USB cable or port. This method should theoretically work even with a charger, but seems silly when you'll have to connect it to a computer to restore.