Can barbecue charcoal be used as a filter in aquarium?

I have few big chunks ofcharcoal in my tank purely because of vivid black colour. I've boiled it about four times for about 30 minutes each times changing water after every boiling session than I've dipped it in bucket of water for a week. It's instead of driftwood. and is been at the bottom of tank for moths without breaking in to pieces or making any mess.