Byfar the best strat for getting maximum fertilizer, first get yourself a Phiomia and slot cap yourself with feces or as much as you want, next take off all of your armour, then set dung beetle to neutral, and victim item collection, unclaim beetle, hit it and then it will aggro to you as if it was wild, but still with the settings you left it on, let it kill you, it will collect all of your inventory of feces which can be hundreds instead of 12 or whatever it’s base weight is, this is called over capping and since you’ve slot capped it, it won’t be able to move! So set it to wandering and it will just sit in one spot while making you fertilizer! I hope it’s helpful (PSA unclaiming isn’t always an option, so make sure you know your server rules, it works on official tho! Hope this helps!)
Get yourselves a Phiomia as well! Feed it stimberries and you'll have plenty of medium feces to throw in the dung beetle. Fill it up, and come back and watch more fertilizer than you can imagine. I'll never use compost bins again!