Dental mom here- there are no at home remedies to treat cavities. Oil pulling helps prevent the formation of cavities, but does not reverse the damage. There are alternative toothpastes out there- ask your dentist about MI Paste, that’s what I use on my toddlers. Cocoshine also makes an effective fluoride alternative toothpaste and PFAS free floss
My daughters teeth rotted right off the bat of growing in she had to get her 4 top teeth pulled and four caps in the back… I’m sorry that’s happened