I dont know about bear crack but I know of a simple way to get bears to come in. Get yourself some carp the year before you plan to hunt, put it in coin sacks in a bucket, and burry it underground. Let it sit for a year. Pull it out the year you plan to hunt and it will have turned to a liquid. Find a small tree that the bear can not climb and is out of reach and hang the bag in the tree. The liquid will slowly drip out. Word of caution, bring nose plugs.