I have a pair of brand new black cotton pants that got mixed up with old prawns/shrimps (don't ask me how!). I have washed them in both cold and warm water (about 6 times), soaked them in Napisan (nappy soaking solution) and hung them out to dry in the sunshine. How do I get rid of the smell?
A bottle of cod fish oil broke in my fridge (since it has to be refrigerated) and my son wiped it with a towel. I could not take the fish smell out after 4 washings. I was going to toss it out until I tried washing it again with baking soda and it seemed to work. I had to wash it in the soda at least twice before the entire smell came out.
You could also try soaking in vinegar diluted in water ...
I'd try the baking soda.
This is a weird suggestion, but I had fish smells in my refrigerator and someone on this site recommended putting plain newspaper in the fridge.
I did it for several days, changing the newspaper each time and it worked!
Can you put your plants in a plastic or maybe better, paper bag with some newspaper and try it out?
Good luck!