Yep they will hand feel, as will most things if you gain their trust (ie, dont chase them around the tank with your hand).
Use big meaty foods like prawns or earthworms. Hold your hand under the water with the food in near the bichir and after a bit it should come out looking for this food it can smell. Once it has eaten it, take your hand out and do it again in a few days when you next feed him. Eventually, it will get the idea that you hand means food, and will linger around when your hand is in the tank for food. At this point if your carrying out mantinence, watch him constantly and keep your fingers close to your hand in a fist so he doesent think one of your fingers is a prawn.
Good luck!