Unless your friend is running an underground filter system, there's really not going to be that
much bacteria found in the gravel to help a cycle along. What you really need is a chunk of filter media from someone with a mature - and cycled - tank, which will hopefully contain enough bacteria to jump-start your own tank's cycle.
It's why people with small unfiltered tanks can't cycle them. Only a very tiny amount of bacteria is present in the gravel and water column. The type of bacteria you need to establish a cycled tank, grows where there's the most oxygen and flow, which is in the media of your filter.
So unless your tank is going to be filtered, I wouldn't bother even trying to cycle it