Baby toy

I was given am exersaucer and there’s little black dots on it. I scrubbed the plastic thoroughly and it seems to be all gone. However there are multiple toys that attach to it, some that use batteries and the straps on the bottom have the black dots on it as well. Would it be okay to replace the straps with velcro? Replace the toys with straps all together? Or throw the whole thing away in case there’s mold I can’t see on the inside of the main unit?