Styx
Fish Addict
Are live black worms good betta food or bad betta food? What are the risks of feeding them this particualr food? What are the chances of them getting internal parisites from live black worms?

Why only me are so different one in here??? LOL 
It's more apt to be your supplier. I got mine from the local LFS... they were clean... no dirty water with them, etc. I washed them in clean bottled water daily. I put them in a plastic zip lock box with water in the fridge. Every single day I cleaned them with fresh water. When I went to feed the fish, the worms were again washed in clean bottled water - TWICE. My fish loved them too, but I began losing fish at the rate of one or two a week from them. I cut back on the number of worms each feeding, still had loses. Bought from another LFS - still had loses. I actually bought from three different stores in areas around Long Island. We also have no idea just how the LFS is keeping the worms either.
I remember seeing somewhere that frozen blackworms do tend to get a bit mushy.