There's this theory that you can dilute the chemicals by doing frequent blood donations.
new blood replaces them so they're back to where they started, but you're down a bunch
“In this randomized clinical trial of 285 firefighters, both blood and plasma donations resulted in significantly lower PFAS levels than observation alone. Plasma donation was the most effective intervention, reducing mean serum perfluorooctane sulfonate levels by 2.9 ng/mL compared with a 1.1-ng/mL reduction with blood donation, a significant difference; similar changes were seen with other PFASs”