Child ate gunk from the sink

I’m not sure what to do after my child ate some gunk from the sink after gaining access to the bathroom and took her toothbrush to scrub inside the hole of the sink and ate some of the black gunk that came out of it. I panicked and tried to induce vomiting but it didn’t work out and accidentally poked her in the back of her mouth despite having super short nails causing her to bleed :( , I felt super bad but I thought at that point of time I could get some of it out because I’m scared that she’s going it get really sick from it. I so worried and I’m not sure what to do, should I take her to the GP? We moved into this rented apartment few months back and god knows what’s in there, even if the house is brand new, I’ll still be worried.

I’m also not sure what I can do being home alone with a 2 year old that is tall enough to reach the door handle, I am not sure how I can keep a lookout on her while doing other things at home as she has access to all the toilet as they cannot be locked from the outside. Should I just remove the step stool? She’s at the stage where she’ll eat anything brown thinking it’s chocolate and I bet she thought it was oreo. Do I just wait and see if she gets sick or do I take her to the doctor. I read online it should be some bacteria biofilm and MOLD. Help…..I know I should’ve kept my eye on her but how do I get things done at home…