I really like mixing up the bait in my tubes or bait cages...I'll mix Macks, and Tuna bloodlines with Bonita heads and trimmings, then I usually pour some additives on the bait cages once they are in the ziplock bags. Then I'll freeze them and leave them semi-frozen until I drop them. I really think the scent/additives work...I've done some tests with scent only with the GoPro camera and it works. With scent only the critters won't stay in the net but they will go in there to check it out.
Menhadden oil is good, so is Salmon oil, although its pricy...this Crab and Shrimp Fuel by Pautzke is affordable and it works. It's about $10 a bottle.
Save those tuna heads and bloodlines...there were a few Skipjack in the counts the last week...if you can get your hands on any of these bloody Tunas...you'll be on your way to a limit of Bugs.