Easiet way to just clean the tub trap is hold a rag over the over flow hole and Plunger the waste .
If you don not hold the rag over the over flow opening you can not create the vacuum needed to clear/ break up the stoppage.
FORGET CHEMICALS.. Using a snake the proper way is through the over flowmopening NOT through the tub shoe as your now going through more 90 degree fittings then are necessary.
Snaking from the over flow is the direct route to the trap as normally your going through the “RUN” of the tee and not the BULL end as this connection is for the tub waste. By going though the tub waste your hitting 2 more 90 degrees than going from the top opening. Hey have fun that is the main thing
UNLESS you have a Lay Down tee Or side outlet type the easiest BEST way to rod it is overflow strainght down