High-temperature steam and steam plasma are available today.    See for example here.

Destroying PFAS with temperature is possible.  Reports place the temperature at between 500C and 1000C.

ACS EST Engg. 2022, 2, 2, 198–209
Publication Date:January 11, 2022
Other high-temperature quick methods are with the Airtorch and other products listed on www.mhi-inc.com.