Hey Steel probably the safest way is to make your own mix to repel the deer. Bambi might get caught up in your fishing lines or even injured. You might consider a 30/30 depending upon where you live but remember Bambi! ? I can't remember but in the 1950's I think in was some type of fuel/coke used at Bethlehem Steel in Buffalo NY that had a rotten egg smell from the furnaces I know regardless back then and now that various rock is available that has that basic smell but would it be a strong enough scent? Try a bit more research interesting but animals are animals doing what they do best.