Zyn on fast days

Hi! Shalom ubracha

Regarding nicotine pouches such as zyn, VELO etc…

¿Is it ok to use them during a fast day?

( It releases flavor that can be swallowed with saliva, although it is possible to be careful and not swallow or even spit it.)

Thanks in advance, shenizke benejhamat tzion

No need to spit.