Jump to 1:40 in the video you're talking about. She literally says "So, I did not get implants, I did a fat transfer".
As the above said, saline infusions are a temporary size increase that the body reabsorbs within 24 hours. She does that for an extra bit of size increase now and then because she has a breast expansion fetish.
Adding more fill to an implant isn't something you would ever want to do at home unless you had a literal port installed on your skin.
Watch any nude video of her moving around a lot from before July 2024, it's very clear there's no implant inside sliding around, the breasts move around, stretch and flatten as one unified mass, something only fat transfers can do.