I salt and freeze blowlug. Dig them. Put them in a pile of salt for 2 hours. Wrap them in 10s and in news paper. Put them in the freezer. They work really well and I always have bait. In fact I did 200 on Wednesday.
I just was them with sea water so they are clean and not sandy. Then I get 4 sheets of newspaper, put a layer of salt on it and lay the worms out not touching. Then cover the worms with salt and leave for two hours. I don't gut them or do any over preparing, just fresh worms in salt. As It happens I went fishing last night with some and caught 5 or 6 dog fishing, 2 black bream, a Pollock and a couches bream. I am just as happy to use them as any over bait.
Just one thing wrong with that, you put them in news paper that's covered in INK, which will absorb into the worms as the oiks saturate the paper. You can smell ink on your hands when you handle a pack of lug like that, so will the fish, and last time I checked ink wasn't a natural thing for fish. Lungworm breath through the feathers all down the side of them, that's how they absorb the ink.
The one thing we didnt mention is, they preserve best if you immediately freeze them for 24hrs after wrapping them, then you can keep them in the fridge or somewhere cool.