I'm so paranoid. Loose items scare me. My baby sleeps face down (also scary). I did at one point put my night shirt under her sheet in her bed. That way she could smell my scent but couldn't pull it over her face. Tbh, I'm not sure if it worked but it's worth a shot.
Maybe try tying it to the bars of the crib or even using a yarn blanket with big “air holes” and tuck it under the crib mattress so baby can tug at it but not over the face? My mom watches my baby for me while I work M-R and she always has like 3 blankets on her and isn’t smart about these things. Scary.
Hmmm I think I only tried this once or twice, hoping my scent would keep my son sleeping through the night but it didn’t work. I can’t remember if I was nervous about it being in the crib though