I put a house down in the water in the swamp, surrounded it with spikes, walled in the perimeter and went afk in the house for a few mins.

Came back to broken spikes but also 20~30 bloodbags.

Just make sure it's open to the ocean, and walled in and torched up properly against other unwanted mobs.

Originally posted by jonnin:

10 bags makes 1 round of healing mead and a couple of puddings. If he wants to use those consumables in bulk, its going to take large amounts. I go through a fair bit... just a walk through the water in a minor swamp got me 20, almost 1/min or more. The trouble is that pudding takes thistle, which is slow farming.

Some seeds have bad thistle clusters. Some have excellent thistle clusters.
Make sure your seed is good!