Foil cover went in coolant resevior

So there I was performing the 100k mile coolant flush on the wife's 2013 Explorer limited 2wd... After puncturing the little foil seal on the bottle of Prestone radiator cleaner, i began to pour the cleaner into the coolant reservoir along with distilled water when the little circle foil seal that was still attached to the bottle came off and went into the reservoir and then the engine. I ran about 4 gallons through the coolant system to try to get it out, but I'm pretty sure it did not come out. Am I fucked, or do they make those things so that they somehow dont hurt anything? Thanks in advance!