Blu-tack? (sticky tack) toxic for bettas?

[Kira and Cleoh]

I found something for my female to hide in because I'm setting up to breed, but when i was sand-papering it down because this one part was a tad sharp, and i found tiny bits of sticky tack all over, I think i picked all of it off but will it harm my betta's if i put it in there? Im going to be washing it too,

[ChoclateBetta]

I say no first off inside of fish decorations from what I have seen then little pieces everywhere bettas love live plants.