I don't think you can neutralise the shed if they've already been in there. Rabbits have an incredible sense of smell & can distinguish between smells easily.
Thumper could tell if I'd had any physical contact with a dog when out, & reacted to me on my return as if there was both me & an (invisable) dog next to me = run into hiding even if I washed my hands. I had to change my clothes before I went near him & allow dog scent to get stale.
There's a slower method of bonding which some people use.
Maybe try a thread about slow bonding for more replies?
I know Halfpenny uses it but rarely posts now, & gets pressured with her own rescue. Maybe try some of her old threads.